This thing is supposed to be LESS resource intensive and perform BETTER?

With unchanged options and the same download list:

4.8.1 4.9.0
170meg 225meg!
High cpu use High cpu use
70-odd threads 40-odd threads

Fewer threads, at the expense of needing more RAM and no less CPU than earlier versions.

Also, 4.9.0 has a nasty habit of hanging for several seconds (sometimes a couple DOZEN seconds) after completing any download. It simply stops responding completely for this time -- whatever it is doing consumes 100% of a 1.5GHz CPU during this time and takes priority over UI event handling(!) -- if it's like that for 10 seconds that means it performed around 15 billion calculations to do whatever the heck it's doing. What the devil is an event-driven app doing performing 15 billion calculations in response to a network event? The previous version (same size library, same size downloads list, and only the search/download tab visible) didn't exhibit this behavior -- though it did if the library tab was visible, queerly enough.

It also seems to be quicker to give up on a file and say "Awaiting sources", although it seems to be quicker (when it isn't hung, that is) to do some other things also...