Yes, those shortcuts are there, but as far as I can tell, (a) they're fixed, not configurable, and (b) the ones I want aren't there. My workflow in C1 is to move quickly from shot to shot, cropping, adjusting levels and contrast and occasionally WB and saturation, and moving on. With the exception of the crop, I can do all this from the keyboard: ctrl-arrow to move to next shot (LR is same except I get "Loading..."), ctrl-+ to increase exposure, ctrl-shift-+ to increase contrast, shift-+ and alt-shift-+ to bump the WB, ctrl-alt-+ to boost saturation, etc. Hit Insert and the image starts processing in the background, ctrl-arrow to go to the next (which pops up instantly) and so on. I can buzz through 200 images in an hour, and never have to touch the mouse except to crop.
As for why I'm thinking about switching, well, I shoot a lot in terrible light, and the difference in what LR3 (and ACR 6.1) does for my 1D Mark IV high ISO images (north of 3200) as compared to C1 is, so to speak, night and day.
But with the workflow differences, I'm thinking I'm going to have to stick with C1 for most stuff and only use LR3 for the really ugly high ISO images.
The machine, BTW, is an AMD Athlon 64 X2 Dual Core 4800+ at 2.4 GHz with 4 gigs of RAM, running XP. Hardly the latest and greatest, but C1 v5.1 is reasonably snappy on it, as is PS CS5. I agree with what you say about the rendering delay of C1, but I've gotten used to it, and it's not even remotely as irritating as watching "Loading" each time I move to a new image.
I wonder if installing Win7 64-bit would help? Or is it that I don't have my previews set up right?
Nill