I had the Exploration Set as well, although I didn't use them as toys because they were so breakable. As I recall, the phaser grip didn't stay on at all.
Or perhaps it would be more accurate to say I didn't use them as toys after I broke them.
My dad did most of the model assembly and as I recall, he had a lot of trouble with the decals. I believe some of them went on wrinkled. My mom got in on the act and painted some of the communicator buttons with red nail polish to add some variety. Probably not very screen-accurate, but I thought it was cool.
I remember really, badly wanting the "Star Trek Communicator" (presumably the Mego one), which was very obviously a working device and therefore head and shoulders above everything else. Unfortunately I never got it. I did get some generic walkie-talkies within the next couple of years, but it just... wasn't the same.
The generics were good enough to annoy the hell out of all the CBers in the neighborhood, though.