I know this will open things to debate, but I have found that with a Helles that a decoction (even just one) brings out a better flavor than simply using Melanoiden malt to get some melanoiden richness. Has anyone else found this to be the case?
I don't use Melanoiden or decoction...I guess I feel like I get enough maltiness out of just the malt and the right water additions. I don't want it to be crazy malty like a doppelbock, helles is supposed to be SUPER quaffable. Everyone here knows that.
As far as opening a debate, I don't think decoction is worth all the work. But that's apart of what this hobby is about, putting into it the amount of work you want.
But then again, I also think that I get enough hoppiness out of late addtions in the boil rather than dry hop, so take my opinion with a grain of salt, obviously...