Pros: The price is good and it is light-weight. The wired interface never bothers me and I love not-dealing-with batteries. It never misses keystrokes (which is sometimes a problem with wireless). I also like the few extra convenience-keys for play, search, etc. Overall, I'm happy with this one.
Cons: I had the original Microsoft Egronomic Pro. It was really great, but it is no-longer being made. This is the lesser-version of it. It feels a little cheap, but it still works well & has been reliable after 6 mo (so-far). My biggest complaint is that it is not the original *sigh*. I just don't expect it to last 20 years like the last one. We'll see, I guess.
Overall Review: This is the newer (cheaper, lighter) Ergonomic Pro. The layout is the same and it performs equally. The wire is a nice feature for desktop or dock, IMO.