Lightroom 4 vs. ACR vs. Canon DPP

Ok, if somebody could give me a quick answer I would appreciate it.  I will continue searching in the meantime, but if you know and are willing to share then great and thanks!

I’m considering pulling the trigger on LR 4.  I first used RAW files in 2005 out of my Canon G6 and soon stopped shooting RAW + Jpeg in favor of Jpeg only.  I went back to shooting RAW last summer on a trip to Colorado with my G12 so I didn’t take any chances with those images and since trading up to a G1X recently I’ve been shooting everything RAW + Jpeg.

Basically, I am familiar with RAW, but not really too familiar with tweaking them well and I am seeing more of the plus side to shooting everything RAW + Jpeg with increased storage space being less of an expense, etc. It’s almost become part of the ‘fun’ of the hobby to be able to tweak on my images.  It can be a hassle too, but rewarding afterward.

Anyway, from a few of the video tutorials that I’ve seen I seem to catch that Lightroom has some abilities that I don’t believe I have in my current programs DPP and ACR.  This is what I’m curious about; is it true that I can’t do the selective adjustments that I’ve seen in these tutorials that appear to be what might be referenced as ‘layers’ in Photoshop possibly?

I would love to be able to more selectively apply the RAW tweaks to my images as opposed to the entire image getting the very same treatment which results in an image that is unbalanced or compromised to balance for the subject focused on, etc.