Anyone ever use one of these for guitar? I love the small size. I'd like to get an envelope filter for my guitar and also one for my bass, but have it fit in one small box and only pay for it once!

Is it too optimized for bass to be fun with a guitar? While we're at it, how is it for bass, anyway?

I have one. It's pretty modern sounding - a little too perfect; but it's a great size, and it can do normal upward drive, sharp upward drive, and downward drive. It's so clean and perfect, it might be a little better for bass than guitar, but I like it just fine for guitar, better than either little DOD box I tried.