Room acoustics make a big difference, too. The Wurli in the Castro Theatre is San Francisco has this incredibly lush, rich tibia sound that is not duplicated anywhere, and I think the auditorium's acoustics make much of the difference.
Also, the 2/12 Wurli in the Mt. Baker Theatre in Bellingham, WA has a set of tibias that just have to be heard to be believed! Lovely theatre, too!
In general, I'm not a big fan of the super-fast "chattery" sound that most British installations originally had. Fortunately, most of the recordings of somewhat recently-restored British organs that I've heard tell me that modern restorers have gotten away from that sound for the most part, slowing 'em down just a bit and deepening the trems a bit, also.
Q: How do you make a theatre organ sound like a church organ?
A: Take out all the GOOD stuff!