My EW-modded AU-919 was recapped EVERYWHERE...and I still felt a qualitative improvement with the 640P. Do't think it's quite where I was with the Stingray and the Black Cube SE, but the AU-919 fits my needs better, and the 640P provides a better price value proposition than many more expensive phono stages, IMO.
Hey - if money is no object and you want to spend $1000+ on a cartridge, I can't expect somebody to not maximize the quality of the signal coming from the cartridge (hence dropping some additional $$$ for the rest of the food chain - up to and including the speakers. But for those trying to make do with a $100-400 cartridge and a $250-500 TT (like me), spending an additional $200 on a decent phono stage can be a good option. My entire vinyl rig was less than $1000 (used MMF-7 and Benz Micro ACE cartridge and a new 640P), and I think that it provides a great source for the buck. I would think that any half-decent cartridge will improve with the sub-$200 phono stage options that are out there (like the 640P) - as with nything in this world, it's how much you want to spend and how good does it have to be.
This is a GREAT time to get nice price/value setups, IMO.