That's a good price - but it is a discontinued model (the new ones with end in 30, not 20 BTW). It's a very nice TV, made in Japan. Basically it's a Panasonic V20, but with the option of watch 3D / converting 2D into 3D. It also features a regulation Panasonic black surround, not the grey one found on a V20.
Basically, if you like the V20, the GT20 would be a go'er.