It looks like the changes are improving downloading low seed files.  However, when the bandwidth->priority group is set to UHx10 it does not appear to detect a well seeded file and prioritize it for download.  It may pick up one or two seeds (out of 100 for example) and download relatively slowly.

Priority does not relate to number of connections.
More connections doesn't mean more download speed.

for me version 2.49 had trouble connecting to peers, outgoing connection seem broken, reverted back to 2.48

can someone test it?

This is also my experience.
I have reverted to version 2.48.

It would seem to version 2.49 in some situations simply cannot connect to certain other clients.
I dont know if there is anything special about these client.
All I know are, that when I reverted to version 2.48 my upload speed was back to expected value.