4k mean :
1) more space to reframing also to stabilize only or rotate picture to have correct horizont
2) better hight freq dectails that allow you to delivery crisp and smooth picture without moires or other artefacts
3) quality for future distribution in 4k
4) enable to have on interview and many other "news" situation ability to zoom and cut from pp to another with single shot
5) better quality to mask or tracking, and also if no one want to do it, you ever found something to adjust and this mean you have more room to work
6) 4k mean no aliasing or other problem during rotation of shot to add more motion or compensate error
7) you can extract frame at 9 mpixel to print or use for xx reason, i shoot most of my time in raw, that mean i have a photocamera that shot only 9mpixel photo, but 30 raw picture per seconds for 24 minutes continuosly, when you can found something of in photo environment?
8) print to film for theater is different very different from 4k to 2k master, too long to explain, but from a 4k you can deliver a very full 2k 4:4:4 sampled channel that you cannot do from most of 2k sensor (bayer matrix reason) (i talk about 4k 10-12 bit, not 8bit 4k)
9) denoising from 4k is simplier, and better, and keep more dectail
10) green screen and and other have more dectail and info to key correctly color

Cons :
1) use more space... ehm don't you remember how many space use dv-dvcam for their poor quality against a simple HD?
And more... if you a bit of money to buy or rent a camera to shoot in 4k you have money for hard drive to stock and manage it. I edit 4k prores of my bmp4k from my simple 2012 notebook hp with 4gb of ram 2 a 256 gb ssd for Os, a second internal disk and usb3.0 and esata external disk... or with my desktop assembled at end 2012
2) take more time to render? it's probably a time to update your edit machine, if you work correctly with DI (prores, cineform, dnxHr) you render is since double time of old HD, not need more, or you have bad configuration.
3) you hate 4k, be cause that mean better focus attention, better light, better makeup on people, better attention to background, better lens that show my lens are crap and more...
Ok it's a your problem, come back to minidv and then upsample to hd and you are happy [obviously this is a joke reason :-PPP]
4k need more attention and more quality in all part of chain, be cause show all defects, but also all quality. please see a real 4k shot in a good projection and you understand why 4k is better, in 4k tv that blast all contrast, color, high low freq dectail probably you see less difference, but is not 4k, is a bad tv with bad "enhancement" that degrade picture

recently i discuss about Creativity and freedom of subject of 80' movies...
after an animated discussion with a guy i did a small list...
1984 vs 2014....
in 1984 we have many cult movies, only few sequel (great sequel), in 2014 we only sequel, reboot, remake, retelling and few more...
in 2014 i remember only Guardian of Galaxy, shooted and directed in 80' style :-P and Birdman
and i want to avoid to start with 1985 that have gems like Back to the future, Goonies, Legend, Brazil, and more...

1984

Gremlins
Amadeus
Terminator
la storia infinita
Ghostbusters
C'era una volta in america
Karate Kid
Nightmare on elm street
Footloose
Police squad
Indiana Jones II (sequel)
Dune
Beverly Hills Cop
All'inseguimento della pietra verde
StarTrek 3
Conan il distruttore (Sequel)
Orwell 1984
Nausicaa della valle del vento
Splash una sirena a manhattan
Top Secret
Paris Texas
Urla del silenzio
Giochi Stellari
Omicidio a luci rosse
Greystoke
CottonClub
Philadelphia experiment
Starman
Passaggio in India
La signora in rosso
Runaway
Birdy
In compagnia dei lupi
Ghoulies
Dreamscape
Electric Dreams

2014

Lo Hobbit terzo capitolo (sequel)
i guardiani della Galassia
Interstellar
Una notte al museo 3 (sequel)
Hunger Games 2 (sequel)
Tartarughe Ninja remake
Scemo e più scemo 2 (sequel)
Big Hero 6
Birdman
The lego movie
I pinguini di Madagascar spin-off
Maleficent
Ape Revolution sequel-remake-retelling
I mercenari 3 sequel
X-men giorni di un futuro passato sequel
Lucy
Transformer 4 sequel
CapitanAmerica 2 sequel
Hercules il guerriero remake
Spiderman 2 il potere di electro sequel
Noah
Rec4 sequel
Sincity2 sequel
Dracula Untold (retelling)
Godzilla remake
300 l'alba di un impero prequel
Robocop (bad remake)
I, Frankestein (retelling)
Wrong turnb 6... sequel

the eason of bad cinema earning is that there are too much bleach copies of old movie and not innovative ideas. When i talk about bad earning i mean, that if i spent 100 million of dollars and i do 300 million i did a bad business, be cause i risk 100 m to earn only two times (100 i spent it) in how many times?
very box office are movie like Terminator, that earn twenty times of cost.

3d was born with Cinema and Lumiere brothers
https://www.instagram.com/p/RCjj3-rOvA0CLK5OHIoYg-ulgcwXBSBI6r0AA0/?take...
Is responsability of Artist if a tool is used to do a Wow effects or to add a deeper emotion.
i can critic in the same way the abuse of shallow of depth, instead to use light to build plane, or abuse of every tools...
3d can add more emotion in a narrative, but it require new rules to work in shooting and editing, most of 3d movies are worst conversion from 2d to 3d, or wrong shooted without a real knowledge about percetion rules of 3d.
I saw only Hugo and The Hole (joe dante) with good 3d emotion without Wow effects in live 3d shooted movie.

i love phisical support, i had over 2000 vhs, 1800 dvds and i started later with bluray (be cause most of first bluray ediction are rubbish, an upsampled version of sd movie .... ).
But...
when i release my movie i think first to theatrical and Ondemand distribution, be cause i must see not what i like to have, but what market use, now, that mean DoD, Streaming, Itunes, Amazon video, and similar...
Naturally i will do dvd and bluray iperEdition with lots of extras and Backstages, but only for fans, a very limited edition, less than 1000 copies for all, be cause... i think only people that love my movie could by it, and i want to produce my special way to tell thanks to people that will love my movie, like peter jackson did with The frightneers that produce a special contents for laser disk and three disk edition of dvd and bluray, with all that himself want to see behind a movie.

do all registrations to have all rights reserved to you about your idea, later diffuse it...

my suggest is simple, nothing that you not use directly...
the unique right way to build something is to use youerself and find strong and weak point of that tool... there are tons of rubbish in the market, produced like copy of xx brand, cinecity.com is indian producer that copy most of highend gear, something are nice, like cage, many other where there is mechanical and logical rules that they simply copy without understand it you find a unusable tools, be cause they not tried to use it, calibrate or balance on real enviroment work.
invest your time to use some tools and do better, a simple copy of tools is a risk of producing bad tools.
Example: focus gear for lens, you see on market a lots of way to put a gear around a lens, but most of them lack of first thing, are not professional usable be cause who produce them think only about to lock strong around lens, but not how to use them in right way, then you can see wrong external size, bad joint point, and more...