So that we can have an opinion from the other side of the fence...
I have been running re-routed vacuum lines on a S1 setup since March or so of this year. I took the green and black line off and routed my vac. setup from the compressor housing (green line nipple) to the WGA (agp wga). I set the AGP wga at 15#'s and spliced in a MBC between the compressor and wga setting that to 18#'s. I was running high 10's low 11's :1 a/f on that setup. I am now currently running 19-20#'s on this setup and getting mid 11:1 a/f on my PLX m-300 wideband. I do not have means to monitor my EGT's at this time but from what I understand from others, everything is koshier.
For reference my mods are...
S1, AEM intake, stated vac. setup, 19-20#'s boost on 93, 3" turboback, ED intercooler, 3" cutout (a/f raises a touch with cutout open as boost raises 1-2# also), no cat, NGK plugs at .038