I just sent off a couple of tracks to a mastering service that uses an Avalon 747 to see how they turned out, and see if I want to rerecord them. Their website is Inpulsemastering.com
if you want to check them out. They have some API pre's as well but I'm pretty sure he uses the 747 primarily. I did notice a somewhat edgy film over the overall sound, but it's still pretty good. I'm going with a UA LA610 for my first high end strip. I love the thick, sultry, slippery sound that they produce. I was planning at some point on getting a 737 but I dunno. I could probably get a good pre and seperate comp for the same price that might yield better results. I dunno. I surely plan on getting a good Manley Vox Box one day though! I used some sort of Manley with a U87 back in '97 and was super impressed with the sound of my voice through it. Never have quite achieved those results since. I will in time though and more. More. More!!! HAHAHAHAHA!