I am not a pro processing huge batches of wedding photos or product shots with deadlines. I am just a hobbyist who processes his shots in between stints at the office.
My workflow is I process one RAW file at a time - giving each shot it's maximum attention - it's a therapeutic process
I'm in no rush. I had used ACR for several years only switching to LR in the last year. I find myself reworking many old files as I find the improvements to the various noise reduction/demosaic/sharpening ect. algorithms in LR3 make a big difference.
I find that LR processes each of my ancient 30D files slower than ACR (CS4 version). The speed difference is noticeable. The difference is large enough to cause me to ponder why. I would have thought/assumed LR would process each one faster as I figured LR's footprint was smaller than CS4/Bridge's.
This isn’t a complaint. I am not leaving LR – I love it. I find it so much easier to implement presets than with ACR. Its develop presets it saves me plenty of time. The history states allow me to back up easily if I’ve overdone something. There’s plenty of reasons I can’t articulate now why I don’t miss ACR.
Just wondering why it takes longer than ACR to render a single RAW, cuz to ME it is counter-intuitive, that's all. I figure the bigger brained people here might know.