What did you have trouble with ? Last August sounds like a xT-30 model ? Or was it a different brand ?
Unfortunately, any TV can develop problems. The xT-50 line has not been out long enough to assess long term behavior. They could all explode in a giant fire ball at 366 days if all the plasma goes super-critical. Hope thats not the case.
Overall, the GT50 appears to be a very good performer. It has a few personality quirks that rub some people the wrong way but its probably one of the 2012 market leaders in plasma.