The C1, without a doubt is superior in performance. As you mentioned, the usb bus is separate from the ethernet and it makes a massive difference. With 1gbit ethernet and a quad core 1.5ghz cpu, it makes the RPIv2 feel like a snail.
Now the downsides with Odroid:
Make sure you get a Odroid C1+ (plus).
The previous Odroid C1 (which I have) is plagued with poor SD card support. Users with Samsung SD cards reported issues (hangs, IO errors), and Odroid confirmed it. They claim this is fixed for the Odroid C1+.
- I’ve had nothing but issues with their official PSU’s.
My XU4 PSU was faulty on arrival and caused me days of issues. My C1 PSU lasted a few months before it too caused issues. Both caused me filesystem IO errors, crashes and system hangs. Replacing both the PSU’s with better quality resolved all issues.
There is no denying the Odroid community is small. So if you experience issues, dont expect a resolution will be available with a quick google search.
Regardless, I love the Odroid C1, its what the RPIv2 should of been. However, if you want quick resolutions and consistency, buy the RPi v2.
DietPi has an image for the C1 and should work for the C1+ (i dont own one so cant test it).