Archangel I've bought a few razors from that seller (don't know him personally) and haven't had any problems thus far. I normally email every seller anyway with questions, and if I remember correctly, he answered in a reasonable timeframe and was fairly friendly.

As far as that razor and if it's a good buy - as everyone is saying it's your call to make. And this is important - that should have been a call made before bidding. Unless there's some significant difference between what was described in the auction and what you receive there's not all that many options for you at this point. He may be a nice guy and let you out of it (he'll still have fees to pay though) but it's more likely that he'll want to finish the sale so be ready to do that.

Assuming you get the razor, generally a DD shows a good shave. As far as how that's effected by the "mods" to it is hard to say. In any case do make sure you send it out immediately to get honed by an expert - having just a Wapi and a not-shave-ready DD you'll be tempted to give the Duck a try - and that won't be pleasant if it still has a rough edge.