I don't have any of the 630, but I do have three VM Ultraflows, three perlick 425, and 7 525's. I also have a stout faucet.
I definitely like the VM and 425's the best because I switched out the spouts for 8mm a while back, and they are just very durable faucets.
With that said, I haven't had any problems with my 525's... yet. I have quite a few of them, but I don't use them very regularly, so problems will likely show up later.
I have been thinking about increasing the number of taps, but I think I will hold off for now, and see how things settle in the next couple years.
I may get a 630, just so I can swap out the stout faucet when I want to, and also so I can see how the new faucet performs.
If they come out with ultraflows identical to the ones I have, that will definitely be the best way though (also the most expensive route!). I do like the stainless shuttle design for some reason.