Ah, if you have the Blackmagic, then the answer is... Neither!
The BM capture devices are excellent... except for their comb filters which absolutley suck. Unfortunately so does the one on the 925.
I'd strongly recommend getting an outboard comb filter in the shape of a DVD recorder and you will get far better results.
If not, then use the SVideo output. The 925 CF is awful, but the BM one is worse.