Just in case you don't know how UPnP works, I thought I'd give you a quick summary as it may help to understand its limitations (apologies if none of this is new to you).
There are three components, the media server, control point and renderer.
The media server indexes your music and decides how best to organise your music so you have fast, flexible access. This is implemented using indexes based on the tags contained within your music files. A very simple media server may present indexes such as:
Code:
Album
Tracks
AlbumArtist
Genre
Playlists
Servers like AssetUPnP and MinimServer allow you to customise these views based on any of the tags available in your files e.g
Code:
Release Date
Original Release Group Date
Release Type (Studio, Best Of, Live, Compilation e.t.c)
Series (The Complete Motown Singles, Now That's What I Call Music!, MTV Unplugged)
Date Added
The control point provides the interface for the user to browse their collection and sends the selected tracks to the renderer to play.
When the control point discovers and connects to the media server, the media server sends the control point metadata about the objects in the initial display, which the control point displays to the user. When the user makes a selection, that selection will be sent to the media server and in response the next set of metadata objects are returned. This continues until the user selects a track, when the control point sends the URL (that was included in the previous metadata supply) to the renderer to play.
Attached is a sample of what's sent between media server and control point.
The control point knows nothing about the music files, it never even accesses them, and if the control point wished to scrape web pages to present artist bio it would have to do so after the supply of the metadata from the media server, in realtime, which isn't feasible. The control point can only really choose what to support, how to display it, and the functionality to offer.
That being said there's a massive difference between media servers, and the effort you put in directly affects the results as in UPnP the only source of data is provided by you e.g. tags, pictures, booklets e.t.c.
In my opinion a comprehensively configured MinimServer and BubbleUPnP combination with rich metadata beats LMS hands down for browsing and accessing your local music (and looks better doing it too, at least on a phone which is my interface of choice). What can't be achieved is the integration of external metadata, but one of the things I do is have MinimServer push allmusic artist and album URLs to BubbleUPnP so I can link off should I want to.
Ultimately it's probably quite simple, if you want external metadata integration then LMS wins, otherwise MinimServer and BubbleUPnP does.
Attached is an image I've used before to describe the various tabs in BubbleUPnP (consisting of 5 screenshots side by side), but it also shows some of the features previously discussed.