I picked up a 6981 to replace a single-tuner DVB-S card, because Channel 4Hd is available in the Uk using DVB-S2 now. Was going to get my usual brand but a single-tuner S2 card cost more than the TBS dual tuner! Very pleased with the TBS - after fitting it and installing the latest drivers for Win7 from the website, Windows Media Center found all the availabe channels including Channel 4 HD. Channel changes much faster then the old DVB-S card. Very impressed and would not hesitate to get another one.
Only downside is no S2 support in GBPVR (or the new version nPVR), which is a shame. Sub the programmer of GBPVR said he would add S2 support if he got a sample card so perhaps TBS should send him one!