Ninetto,
I have DecklinkHD (PCI-X) with my old 2GhzDualG5 for almost a year. Finally this week I´m moving to a newMacPro (PCIe), but I have also bought a new DecklinkHD. Works fine for me. I usually work wirh DVCProHD 720p (25-50fps). The ingest/capture is made by P2 transfer, so I´m using Panasonic codec. The problem is when Final Cut Pro creates a sequence that matches this codec. It´s fine for most part of the job, but I always output a master sequence with Blackmagic 8-10 bit codec. The result is muuuuuch better. Red channel suffers a lot in DVCProHD sequences (it tends to pixelize). Renders are muuuuuch longer but the result is what it counts.