Hi Lindsay,
As I said, my comments on the suitability of the old version are largely because I tend not to shoot in the situations where it had problems. I don't do much detailed investigation of my shots at 100% as I print them to A3+ max and, to be honest, I am much more concerned with whether I have coaxed a good expression out of my subjects than whether there is some colour-bleeding. I fully agree that your mileage may differ. My clients don't care.
But the new version seems to be substantially better from other expert opinions on the web. Again, your mileage may differ:
http://www.lightroomqueen.com/2013/02/26/whats-new-in-lightroom-4-4-rc/
"The new Fuji sensor design provided plenty of challenges for all raw converters. Although Adobe was one of the first third-parties to introduce support, the early results showed some color smearing and a watercolor effect. 4.4 has made great strides, and although the improvements result in slightly softer images, that can easily be offset with a little extra sharpening."
And from the DPR analysis she links to:
"While it's important to recognize that ACR 7.3 and earlier was certainly very usable for many types of X-Pro1 images - especially if they weren't subjected to 100% view scrutiny - there's no question that with the 7.4 release candidate, Adobe has substantially improved their raw processing for the camera's X-Trans sensor. Our hats are off to Adobe for committing the not-insignificant resources necessary to improve support for X-Trans sensor cameras with relatively limited market share. The results speak for themselves and we feel confident in saying that ACR 7.4 RC is the update that X-Pro1 users have long been waiting for."
Personally, I would suggest that the RAW processing problems are not enough to rule out using a Fuji camera (and equally don't make it the right solution for all).
If the Fuji has problems totalling 100 my personal subjective allocations would be about 50 to AF issues, 40 to idiosyncratic operational choices (like exposure bracketing limited to +/- 1 stop, no minimum shutter speed on auto-iso) and 10 to RAW processing. If those 10 have dropped to 7 with the new lightroom it is great but not significant (for me).
As for what pro and advanced photographers choose to use, well I simply have no idea - do we know sales volumes to each market segment?