I tried the beta version of the JetBrain's program a few months ago and I have the perception that performance and resource usage has improved dramatically since then. Version 1.02 has become my main feed aggregator and newsgroups reader. I had been using Sauce Reader for some weeks and I can only now realize how much pain I have been experimenting because of its sluggish startup performance. I am sure that the Australian makers of Sauce Reader will get it right eventually, but the Czech have right now the advantage, and so I am giving them my hard disk space (both readers are free for personal use).
I also downloaded a trial of ReSharper, another interesting product made by JetBrains that adds some refactoring capabilities to Visual Studio 2003. I hope I will have time to test it in the weekend.