I would stay away from the 6.1. Beta. Sindre has even revoked it because there are major problems with the database.
At this moment Subsonic 6.0 is superior in speed to 6.1. Beta.
How big is your mediacollection? I have about 140.000 songs in my database and allthough I notice some delay when I log in, I don't have a sluggish interface once I am logged in.
Did you try to locally log in to your subsonic server (
http://localhost:4040 )? The web interface should be more responsive than.
Did you use taskmanager on the Subsonic server to view cpu-load and network usage? Do you notice anything abnormal there?
You ping your server and get a 20ms response? If that's a wireless connection than it's not great.
I ping my server wireless and get a 2ms response.
Could it be that one of your neigbours is interfering with your Wireless channel?
Or did WIndows update install a new "improved" driver for the networkcard in your server that's causing the problem?
So there's a lot of things to check, but I would start by logging in locally on the server. If the web interface is fast there than you know it's not your server.
If the webinterface is also slow and sluggish than you have a problem with your Subsonic installation.