DV Info Net - Improving my encoding for da Web....?

I've got a couple test videos here I did using a Canon Vixia HF100 (AVCHD) camera; all footage was shot 1920x1080 in 60i and edited in Final Cut Express with the Apple Intermediate Codec and exported as an H.264 MOV file (thru the 'Using QT Conversion' option in FCE with deinterlacing checked) that was uploaded to YouTube.

Test #1 - nature scenes & macro closeups

Test #2 - Austin scenes

I'd love it if you guys would take a look and possibly give tips on how I can encode better. The first video seemed to come out OK and I'm basically happy with it. The file I uploaded was compressed with a max. data rate of 9MBps (entered as '9000kbps' in the export dialog).

The second file has a ton of water scenes on the lake and much 'busier' and contrasty content I think, and when I tried the same date rate it didn't look good at all, so I exported it again with a max of 12MBps ('12000kbps'), resulting in a 500MB file I uploaded to YouTube. It's better than when I tried 9MBps, but it still looks bad I think, especially in the darker shadows in the sunny scenes.

What rates do you guys use to keep the file size from being ree-diculous, but still producing a good file? Should I have gone higher? I'm curious what I could be doing to improve the quality. What do you guys do? WWJD? :-)

Thanks for any advice....