I've never had any problems with my Triumph or Virgin Mobile. Maybe it's because their towers are near me (which I have no clue) or I just have great luck but I love my plan and really like the Triumph. My gf is an accountant for Target so I get a discount on my Top-Up cards, paying $40/month for 1200mins and unlimited everything else w/ insurance (which works well, broke my phone once already and they shipped a new one the next day) seems pretty good to me.
Only reason I'm thinking of replacing my Triumph is because the Evo is such a good deal and I want a better camera on my phone since I have to take pictures of my work for my side jobs. That and my gf's phone is pretty old but still runs fine.
I like VM and will look to stay with them.