Excedrin & Ibprophen. Nothing worse than a headache on set/location. Eye drops for myself as well as for talent. When I shoot weddings often brides and grooms have a bit too much to drink and their eyes can show that In a bad way.
Without going into super nerdy detail HFS+ is Mac format and will work well with Mac. exFAT is pretty much USB drive format, playing well with PC and Mac. (I believe Microsoft actually owns the patent for it)
I've personally seen no difference in performance while shooting on either format. I use HFS+ when I know I will be handling the footage because I have all Macs. I feel like I get faster transfer speeds when uploading footage and I believe there is a bit less chance of card error.
If you need your cards to be uploaded to a PC, use exFAT. If you're all Mac, use HFS+.
At the end of the day I never really give anyone my cards to upload anyway, I just format an external hard drive into exFAT and dump the footage on that to give whoever needs it. So because I'm all Mac, I'm always formatting them in HFS+
Now that you've got me thinking about this, I'll probably time some identical transfers in HFS+ vs exFAT to see if there really is a speed difference.
Oh and both can handle way bigger files than an SD card can and probably will hold for years to come so don't worry about that!