I don't spend a lot of time checking out various front ends or media players unless I have issues with the one I'm currently using. I used MediaBrowser for quite a while as it allowed me to organize all of my movies and various videos while also providing cover art and background graphics. I could never seem to get movies to show up in my Movie Library in WMC, which is why I gave MediaBrowser a shot. At the time I was using PowerDVD and TMT for playback of Blu-Ray iso's, but the results were somewhat sketchy and I could never get consistently smooth playback on every iso.
I started reading about mkv files and XBMC so I thought I'd try MakeMKV and XBMC. The results totally amazed me. Not only did I get rock solid playback of Blu-Rays but I was also able to play the HD audio tracks using the XBMC version of Eden with the HD audio patch. The added bonus was that I could also play individual M2TS and EVO files that I had ripped from HD-DVDs and Blu-Rays prior to using iso's. I never had to do anything special to get cover art and graphics to show up. They just appeared on their own. The interface for XBMC is definitely eye candy and much nicer to look at than MediaBrowser. MediaBrowser is a nice organizer for your videos, but XBMC is the complete package. There's simply no contest, IMHO.