No, it isn't noticeable, but what is noticeable is each pixel of the screen, since GearVR is a pair of magnifying glasses. For gaming, you will probably need a bluetooth joypad, few games work without it.
If you're not that bothered about apps and want something secure why not go for a new blackberry - a good solid grown ups phone. I changed to android last year and still really miss my blackberry. bb10 is the most advanced operating system, it takes me so much longer to do everything on android plus you need hundreds of apps to do what blackberry does straight out the box. Takes a bit of getting use to but amazing once you do.