What were the issues you had with the Charge? Maybe others had the same problem and know of a way to fix things, or a work around?
Overall, I've heard of issues with both devices, but I have heard of more serious problems with the Thunderbolt compared to the Charge. The Thunderbolt is having reboot issues with the latest OTA update, and before that, had significant battery drain problems, with a full charge lasting just a few hours, regardless of use. The other problem, which is semi-manageable is the screen and its washed out look, and I've also heard of light bleed around the edge. The other issue, which I haven't heard as much about recently where times when the Thunderbolt would get stuck in 1X or 3G when in a 4G area.
With the Charge, some users seem to have random battery drain problems. Myself, I haven't noticed it being to bad, but I only just got my phone. Signal bouncing around has been reported to, but so far, when I'm in a 4G area, it stays in 4G unless I send a text or get a call (haven't tried voice/data simultaneously yet), and if I'm in a fringe 4G area, it seems to only pick it up if it is a better signal than 3G. Software may be a downside here to, depending on how you look at it, but so far, this is the best Samsung phone I have used, and best phone overall, despite the current lack of mods (which will be fixed in the coming days/weeks now)