I ordered a Rat clone from Build Your Own Clone (called the Mouse) last year and finally put it together last week. I didn't time it but I'd say it took about four hours. I was worried I wouldn't have the patience for it but I had a blast doing it and can definitely see trying a few more of these.
The pedal sounds great, too, which is a nice bonus. It sounds a bit smoother than a current Rat and the gain knob has a more useable taper, with a lot more travel at lower gain settings. I tend to use it either for a crunch tone, or way up like a fuzz, so that taper is perfect for me.
I ordered the painted enclosure and totally forgot to choose better knobs, so I've got some clear ones on order.
IMG_8438 by Phil Babbey, on Flickr
IMG_8441 by Phil Babbey, on Flickr
And here's my go-to board at the moment:
IMG_8488 by Phil Babbey, on Flickr