Sound — 9
I use this with a Marshall Haze 40 combo and I think it sounds great. It is not that noisy considering how much gain this thing has. When I heard this pedal I thought it would be good for Pantera and Slayer. I was so right. It leans more towards Pantera stuff, but if you tweak it I bet you could find some other tones from it. Their are also a lot of knobs on this pedal so you could probably play most kinds of metal and rock even on it. I give it a 9 because you can play many styles of metal with this.
Overall Impression — 8
I mostly play metal. This is a very good match for most metal types. I have been playing guitar for 4 1/2 years now and own a Gibson Explorer and a PRS SE Paul Allender model. If it were stolen I would probably buy it again because it sounds good and is relatively cheap, they have some used in guitar center for around $40. I do wish that it came with some manual settings for the tone. I would definitely but this though if you want a lot of gain and and play metal.
Reliability & Durability — 10
If you don't know this then you should: Boss pedals are built like tanks! All of them feel solid and have some nice weight to them. I have not gigged with it yet, but I will in a month and will definitely not use a backup. It looks like it could last forever!
Ease of Use — 7
Okay I am going to warn you right now, if you are planning on getting this pedal and expecting it to sound good right out of the box, you might to spend a lot of time trying to find your tone. I could not find a good sound out of this thing from tweaking it, so I looked up settings for it and found two places to look. http://www.hamptonplace.com/tonedepot/settings/bossmt2.php The first link is a link to peoples settings that they use on this pedal. Some of them are good, others meh. Another place to look is the Boss website, you can download the pdf for settings. I got this for free so I don't know if it comes with a manual inside. I give it a 7, because It's hard to use at first, but it sounds good when you have it properly tweaked.