Collective Development PSO1's

I am considering purchasing a pair of PSO1's ('03 model) and just though I'd try to get some feedback on them first. Anyone that's riding them or has in the past please let me know your thoughts. I've heard it's a bit like being welded to your board. I'm not sure if this is a good thing or a bad thing having had knee surgery a few months back.

Thanks in advance for the help!