I really wouldn’t know. I mostly use Adobe bridge which comes with Photoshop CS3. You can do the processing just fine with the options that photoshop provides but some of the other programs just streamline your post processing.
Lightroom seems to be most popular.
Lightroom is nowhere near photoshop.
I spend hours every day with PS.
Lightroom is usually used as a DAM program and it’s enhancement stuff is stripped from Adobe Raw. But if you want to make production quality work, PS is the standard.