the dano stuff is decent... for what it costs.
most of them are direct copies of great circuits (the french toast was a fox tone machine clone).
the spot where they lack would be in the execution... they use cheap caps, cheap resistors, cheap jacks and pots... tend to be noisy and unreliable.
If I've learned one thing in my exploits as a pedal builder it's that quality parts makes a huge dif.
for a metal sound quality is even more important... in order to keep noise down you need shielded wire, 1% metal film resistors, and really good build construction to name a few things...
on a budget($100 or less) I'd try the pro co rat...
I'd also consider a metal muff or a big muff...
for mid grade price($250 or less) I've heard that both the blackstar and the radial tone bone stuff can be good for shredd... but I haven't tried either.
price is no object - active emg + deizel
http://www.myspace.com/mrmikevhisonepieceorchestra