I have been running the 3.2 RC for a couple of evenings now. On my Win 7 64-bit PC it seems to be stable and with no obvious bugs. In particular, using the before/after view is faster than before. However, with the same files and on the same PC it is still noticeably a bit slower than LR 2.7 on a lot of operations, such as simply switching between modules. There is often a little gulp while the application seems to think about what to do next. But I am still experiencing real problems with the Perspective Control. Actually applying the PC is fine, and totally interactive, but once I have used it on an image any further editing with the adjustment brush or spot removal is virtually impossible, as the change in the image lags many seconds behind the brush all the time. Gradient fill is also slow to respond, but usable.
John