Hi Jay,
From my limited research I can tell you the following:
DVL 909/919 - combo LD + DVD players - these players compromise on LD playback quality. I understand they are not recommended for LD transfer as there are many other players out there that beat them picture quality wise for less money. The reviews for these players are here. At the bottom of the page they state that the 919 is better than the 909.
LDV4400 - NTSC only industrial player. No idea if this is a good player or not, but it should have good picture quality being an industrial deck. LDV800/8000 would be better and those go for as little as $20 USD on ebay. What a bargain!
D925 - Full featured PAL/NTSC deck - suffers from a pretty average comb filter which can't be bypassed.
2950 - supposedly marginaly better picture quality than D925, but missing AC-3 playback capabilities. AC3 can be retro fitted though.
Are you wanting to transfer PAL or NTSC or both? The reason I ask is because you mentioned the LDV4400. If you are after the best NTSC picture from an industrial deck, then Laserman mentioned the V800/V8000 players as being very good. Actually, I think he said they gave a better quality picture than any of the USA consumer level decks including the Elite range (could be wrong on that though).
If you are after the best PAL player which also has NTSC capabilities, then have you consdered the V4300D or V2300D? These decks are supposed to be better than those other consumer level decks for PAL. I have a v4300D, but I'm not sure if it's working properly so can't comment on picture quality unfortunately. These players seem to be hard to find and can be fairly costly depending on the seller.
Hope this helps.