I used few different analogue capture cards and my expirence says the best is the cheapest: Manli TV card with Philips SAA7130. On second place is Ati Radeon 9000 VIVO (Theater chip), follows ASUS 7700 with VIVO and the last one is Pixelview TV Pak (BT848 chip). As base for comparision I used only video capture quality (without tuner performance etc). SAA7130 gives the best capture quality and average VHS tape gives (after preprocessing and filtering, of coarse) better picture than ATI captured file. With strong VCD template in TMPGENC ( "very slow") appropriate VCD is even better as original VHS (decreased picture noise, audio cleaned, normalized, filtered etc.) The only disvantage is incompatibility with virtual dub (known WDM / VFW problem), but there are a few another compatible programs (ATV, VirtualVCR etc.).
ATI has captured frame with small thin horizontal lines carefully visible on full screen resolution, I compared it directly with SAA7130 captured file produced with the same video sequence and identicall codec huffy. Final product (MPG2/1) doesn't have this lines but noise level in video is a bit bigger than MPEG2/1 based on SAA7130 capture.
Last two card are in second row because of lack of XP/2K support and much worse capturing.
My last impression is that two first analoge capture cards give better final product than one based on VHS -> DV passthru methode.
Please your opinion about my comparison and tests.