Most people do not like BeoPlayer because (like most B&O designs) it doesn't offer a lot of control in managing music. It does what it does and if you like it, that's great. If you wish you could change how it organizes (especially double-cds), change display, etc., then you will probably be frustrated. I happen to like BeoPlayer because it does what I want with minimal fuss, but I'm also not that particular about how double-cds and/or complilations are handled.
The reason for BeoConnect (I've used it on Mac) is that you can use iTunes or WMP to manage your music (I personally find Windows Media Player a exercise in frustration, but do like iTunes). It addresses the most common complaints of BeoPlayer - why can't BeoPlayer do X, Y, Z like iTunes or WMP. That is, if you prefer iTunes or WMP, then use them. As such, it is very basic. Simple connectivity and transfer. If you know how to setup and map a drive to your BM5, I doubt if it offers any improvement.
Bottom line is it's all personal preference. If you currently use and like WMP or iTunes, then chances are you will not be won over by BeoPlayer. You you might like something different, give BeoPlayer a try. The one advantage to BeoPlayer is that it can play music directly from the BM5.
Stan