I might be wrong here but with such hardware unlock solution like gevey etc, if you update the iOS version there is a very high chance that the thing will stop working and in most cases the solution is to get a new hardware Rsim or whatever it is.
I have never used gevey SIM etc but someone here who has used it can reply better.
I would personally stay away from such devices. Factory unlocked phone will also fetch you better resale value later.
Even i wanted to stay away to have peace of mind…
but before dumping the idea of going with a R-Sim Unlock device, if i could have an idea of what i would be missing if i go for it…
And if its seems i can live with it and a little less risky…
then why not give it a try…