If it's bugging you and going to keep bugging you, get the 410. I bought the 205H, and did so for a couple reasons. Mainly, it was the price tag. But I also didn't want to worry about 4 power tubes and only had a 50W 2x12 cab (now I know you can pull two, but didn't know that then). Plus I thought the JVM2 pretty much covered the tones I wanted.
In retrospect, I know now the OD channel is really OD2 from the 410, not the OD1, but that's pretty easily modified. Also, I think I would enjoy the additional Clean and Crunch modes...not to mention I think Clean Green on the 410 is probably slightly more "Fendery" than on the 205.
BUT, having said all that, I really like my 205H and only rarely find myself wishing I had the 410. Here in the coming months, as I near the end of the warranty period, I'll perform a few mods that I think will take the amp a couple of steps closer to my ultimate Marshall!
Though, I keep thinking I may pick up a used 410 someday if I find a really sweet deal on one...then I'll do all of Casey's mods on it!!
I will also say that doing Charlotte's mod to make the 4-button footswitch into a 6-button footswitch has helped me get past the 6-button footswitch envy!