I have found that Media Players on the Shadow are seriously challenged, and I'm looking for some solutions. I am coming from an SDA and MDA, and I didn't have these problems with those devices. My library has close to 2,000 tracks encoded in AAC format.
Here's what I have run across to date:
(1) Windows Media will play the tracks, but it takes hours for it to process the library, and in shuffle mode it takes 30 seconds or more to play the next track. AVRCP works to switch tracks, but still has the latency issue.
(2) CorePlayer 1.1.1 takes a few minutes to process the tracks, and it takes 8 to 12 seconds to switch tracks. AVRCP also works, with the same latency times.
(3) PockePlayer: I can't seem to get it to shuffle, and it also appears to be response-challenged.
(4) TCPMP 0.71 works fine in shuffling, but AVRCP doesn't work.
One thing I'm tempted to try is to switch the format into WMA to see if the media format is a causal element.
Somewhere I recall seeing some posts about identifying what is in the startup and removing processes to try to improve performance. I'm also looking to see if there may be some registry hacks that may ameliorate the above issues.
I also had the exact same issues. However, all my files were in .wma format so I went ahead and converted them to .mp3 format.
(1) Coreplayer 1.1.1:- works very well with mp3 (I'm not sure about AAC) but completely sucks with wma (it skips after about a minute). It is also fast and only takes about 1-2 seconds to switch songs. Also, AVRCP works well (without skipping) with mp3 files but has the latency issue (it just stops working after sometime. I wonder why)
(2) Windows Media is horrible on the shadow. In shuffle mode, it takes forever to change to the next track and with AVRCP, the music goes blank after sometime. It also has the latency issue.
(3) PocketPlayer 3.2: I hated myself when I tried this player. It is dead slow (almost unresponsive) on the Shadow and when it's running, the phone becames very slow. AVRCP also didn't work for me and also, disables AVRCP on both WMP and CorePlayer when it's installed.
(4) TCPMP 0.81 :- Was very good with all types of media. However, AVRCP doesn't work on it cuz it uses the Widcomm Bluetooth Stack.
Therefore, till there's a registry hack, I'd recommend converting all your media to mp3 and using CorePlayer. The only issue was the latency of the AVRCP.