A big issue with DPP is that there are no real instructions on how to use it properly and efficently, each user is left to sink or swim.
With Lightroom, there are lots of good books and online tutorials.
Lightroom is much more complex than DPP, and you will need some training on the best way to use it, we see questions from Lightroom users all the time that show they do not understand the basics of how to organize their images, keyword them, much less what the controls do or how to best use them.
If you want to use Lightroom, do yourself a big favor and first view the free online Adove video tutorials, and then buy a reference book to refer to for seldom used functions.
You can speedup your editing by a factor of 10, 100, or 1000 if you take advantage of some of the features.
For example, some try to organize photos in folders on their computer like they would if not using a database. Thats not how Adobe is designed to work. You can do it, but you are not taking full advantage of its capabilities.