I gave Google Reader a shot against Bloglines, and I believe I gave it a fair shot against Bloglines but ultimately, my RSS reader will remain to be Bloglines (at least for the time being).
To make things fair, I put a Google Reader toolbar bookmark right next to my Bloglines bookmark. I created a Google Reader Dashboard Widget Notifier to place right next to the Bloglines notifier. And I tested using both for about two weeks.
My only issue with Google Reader is that it seriously hogs resources on my Apple.
I do like a lot of things about Google Reader; such as the list view versus the expanded view tab and many more things but it is not enough for me to switch.
My default browser has to run quickly with my RSS reader. RSS speeds up my life, I can’t let it slow me down.