Anyone know the performance difference, if any, between the BSC621 and BSC621-2D off DRSAT's site?

Please correct me if am wrong, but the 2D model has an independent KU and C outputs, whereas, the 621 has an internal switch going from C to Ku etc.

Cheers, K

Correct, the BSC621 has a built in 22Khz switch while the BSC621-2D does not have any switch so you are avoiding the -3dB insertion loss when going through a switch.

You can still use an external switch with the 2D model however, as long as it is a DiSEqC and not a 22Khz switch as the KU band LNBF on this model is universal and not standard 10750.

Just to clarify, using a BSC621* w/ scalar on a 1m dish, the conical scalar will not prevent the Ku reception correct?

Cheers, K