Every once in a while there is someone villainizing GPS in mobil devices, but up to now I never heard of a single case, which was not either software bug in OS or program or the simple use without a SIM card fitted.
I have flown with iPads from the first one on and yes, there were unstable times due to software issues, but if you rely on it, do not follow every release. Wait for others to test each new release and give programmers time to fix the inevitable bugs of each release.
I collected some well above 1000h iPad assisted now and only had one issue, which was caused by overheating in bright sun. So, sky view is not as important as receiption is well even in tin cans like a King Air, but keep the tablets away from sun exposure as they collect heat.