I should say it's very network sensitive as you have to maintain an active connection or else you get hung up. I noticed several times that if you lose connection, you get no supplies at pokestops and no pokemon spawns. While someone standing next to me sees 2-3 Pokemon, I don't see anything.No. No it is not. If you're having such a hard time with things loading though, I'd suggest downloading your local map for offline use using Google Maps.
Niantic uses Google Maps to render both Ingress and Pokemon Go.
Also try disabling AR, I find it pretty pointless myself so I keep it off regardless.
Google Maps offline helps speed up rendering of map but doesn't help locate Pokemon if connection is weak.
I also noticed that my character freezes a lot when network is potty. I have switched to my Note 4 as the Pokemon hunting device. OnePlus 3 will only work for me in a WIFI zone like in malls.