I'm also running darky's 10.1 rom, and I'm not having any of the issues you mention - it's my first custom rom and I'm really pleased with the results.
The first thing to check would be that you're actually running what you think you're running - it's easy to miss a step flashing the rom and find you're actually still running on stock at the end of the process, so dive into your "about phone" settings and make sure it's got the right rom info in there.
Then I'd check that you've got your Voodoo lagfix enabled. I noticed after flashing that there's a real performance boost with lagfix in place (more than I'd noticed running a rooted stock rom with OCLF activated).
Finally, try with another launcher. ADW is well-renowned, but give something like GO Launcher EX a try (that's what I'm using) and just see if there's any difference.
If all else fails, drop the team at Darky's a message on their site - they seem pretty active and friendly!