I don't own a Frontier yet but plan to soon. Our 2000 Ford Ranger has served us well but time for something newer with less miles. I'll be looking for a 4wd Frontier with 4 doors, auto tranny and a V6 engine.
Our main use is around town with summer trips towing a 2,000 pound tent trailer. Right now the Ranger's 4wd is coming in handy getting out of snowy neighborhood roads. We really don't do off road and definitely nothing that is going to beat up an expensive vehicle.
I had thought about a Tacoma, but it seems in our price range there are more Frontier's ( under $20k and under 100k miles ).
Good luck with your hunt for a reasonably priced used vehicle, I went new because once we got to about $20+k we didn't feel used was worth it any more...and it's hard to find reasonable and good condition in upstate NY together!