From what Ive seen so far, its literally an update only for the Sierra Wireless card that helps with GPS to fix the week rollover that is about to happen.
Usually OTA updates are just "differential" so its not a whole new system download (which would be about 1.2GB), but rather a "patch" of sorts.....after looking at an update log file from when I manually updated my truck to 17.43.01, at least the full installer is smart enough to know if it needs to even bother updating things....it will skip parts of the install if the new version matches the old version, etc.
Back to the OTA....I would think it doesnt even bother touching maps, etc because it should just be a firmware flash for the Sierra card.
My guess is the Sprint network sucks (it does), coverage and reliability are spotty at best so you could end up with a partial or corrupted download, the update attempts to install it and cant but instead of gracefully failing you just end up in a "need to update" loop.
Crappy software from a crappy "software company". FWIW Apple had to update iPhone 4/4S for this same issue (it looks like it uses the same chip as our nav units) and you didn't hear about any problems with their update!