I've had about 4 spindles of Ritek G03 burn at 2X with no issues, however, as happened to SleepyRaTT, I got a batch that didn't burn at 2X reliably - no matter...it burned at 1X and they worked great. So buy these planning on 1X but it is very likely you can get 2X.
Ritek G04 is 2X guaranteed and also 4X compatible (since 4X is not a true standard yet...but it does burn at 4X). It costs more. It has the same physical appearance as Ritek G03, but it basically just burns faster.
Ritek just makes great media, period.