Obviously I'm probably one of the least qualified people on here to offer tips on Phex but I still wanted to share with everyone (particularly those who will read this in the near future and are even newer than I).
Anyway, after finally getting a good connection and actually having incoming connections I would still only get the occasional good download. I'd try downloading all sorts of things and nada. Tonight I finally found something that works....I'm getting DL's on almost everything now. First, I re-ran the program located here
http://trustyfiles.com/help-sw-xpsp2.php and I changed the number of consecutive connects to 100. I then changed the Phex max number of connects to 99 (the max).
Next, I allowed and forced my computer to be an ultrapeer (I have 1.5Mbps connection) and raised the number of connections considerably. Suddenly I had a lot more success. It wasn't enough though so I played around some more.
Next, I changed the connection timeout to 25 seconds. WOW! This made a big change! I guess some hosts don't connect within the 12 second default time because I got a hell of a lot better results.
Lastly I maxed out the number of global DL connections. This made a bit more difference.
Altogether this made a HUGE difference. Previously I would get MAYBE one download out of a hundred to work. Now, I'm getting probably 1 out of 4 and my bandwidth is usually maxed out as well.
I like success!