For what you need, a tablet is leaps and bounds better than any laptop. The portability and battery life are tremendous in comparison.
I haven't had any issues with wifi (as a matter of fact, it's better than my Epic 4G Touch). Like many others, I never used or intended to use the GPS features, so it's not a big issue for me. It may work for all I know, but I've just never had occasion to test it out.