FYI, I'm doing a 6-hour enduro in February. I'm planning to run an Xray T4'13, since it's a tank. I'm a little worried about top deck tweaks and arm mounts shifting in crashes, but I'm not really worried about anything actually breaking.
IMO, tape is as fast for battery changes as anything else, probably faster than anything that requires a tool. That's assuming the tape doesn't need to be changed out. I don't have to change tape (I use Hudy tape) for at least a few race nights. Call it 10 battery changes. I've been told by people that ran last year, that in VTA (ish), a 5500mah battery will do 30 minutes. If tape lasts 10 batteries, that's 300 minutes, or 5 hours. So I wouldn't be surprised if I can do the whole 6 hours using 6800mah batteries on one piece of tape.
I'll be making sure to clean the batteries before they go in the car to help improve the tape life, and keep a pre-cut piece of tape ready for all stops, just in case. But I don't think it's the biggest consideration.