I just bought an 07 F3. It came with the 1.1 stem and the 1.2 carbon wrapped alloy bar. I have an Oval Concepts stem and bar already and I was thinking of swapping them out. The only advantage that I can see though is weight. I can't find the weight of the stock Felt stem and bar anywhere. Has anyone weighed theirs? The combined weight of the Oval stem/bar is about 425 g.

STEM - FELT 1.1 6061 Aluminum 3D Forged with 5° Rise, 142 Grams
If you can't find the bar weight anywhere (I couldn't) and get no other responses, you could try:
info@feltbicycles.com
They've been good about answering any questions I had.

Congrats on the purchase. I love my 06 F3. Not the lightest in the world, but it sure is fast. I hit 34 mph on a flat sprint last week which is a new record for me.