Well my boyfriend and I have had ST phones for 3 years now. I was using the NOKIA E71 and just purchased the ZTE MERIT for me & PROCLAIM for him.
We BOTH use internet, phone, text etc including YouTube, Yahoo, CNN, he does some sports stuff etc. Neither of us have EVER had the problems people are listing here. We have NEVER received a phone call that we used to much data etc. I also just purchased a 6 month unlimited airtime card for my new phone but now im nervous after reading all of these posts.
I will post back in a few months to update any contradicting results from my previous experience but all in all we are VERY PLEASED with the service from Straight Talk to date.
Great signal too.. we are located in Florida.