I own both the older WHs and the newer T3s. There is no difference in quality and fit and finish between the two. The biggest difference is that the WH stocks are thicker overall, especially in the palm swell area. The T3s are thinner, and lighter.
Accuracy seems the same - excellent.
Quality seems the same - excellent.
The only thing that I don't particular like in the T3 is the one-size fits all action. In the WHs, short action cartridges, like 7mm-08, .243, and .308, all have true short actions. Not a big deal, but I just don't like putting a short action cartridge in a long action receiver.
Zachary