It's really a personal thing. I can't tell you to eat oranges if you don't like'em! I have THREE F-100 because I like them so much. It's big and rather heavy but not too bad.

Olympus are fine cameras. I had an OM10 way back in my youth. Are you sure you'll want to give up all the automation and go back to pretty much everything manual? No auto focus, no matrix metering, no auto winding without winder attachment, etc, etc, etc? If so, go right ahead....

Another thing... if weight and size of F100 bothers you, any decent SLR isn't going to be THAT much lighter and smaller. To me, it doesn't make any practical difference.