I have a Crawler/P-90/P-90 HSS set in an original PRS EG. The original EG has a swimming pool rout, but I didn't need to widen it with soapbar P-90's. Tim got the scratchplate for me as it was a very unusual guitar and I didn't want to damage the original scratchplate.
With soapbars you need to remember that the height adjustment screws will go into the body, so while the coil is wider than the strat pickup, the overall size is not that different.
I can tell you that the sound is well worth it. And it looks great too.