This is the 5th generation of Lightroom. There are some problems that should not exist by know.
It does what is supposed to do, but needs improvements. The slideshow feature is too slow to be useful. It does not detect well duplicates importing from a camera. I do not know how it was before version 5, but I think these issues are too simple not to be working on this version.
If you want to know what does work, there are plenty of reviews online.
It is a shame for version 5, I was thinking that Adobe was better at this.