Sound — 2
I've tried it at various guitar stores with similar results. Playing it on Peavy Amps, Line 6, Crate, Engel... and it's the same result. Very High top end with no mids and low end. It tends to be very noisy at high gain settings. Even using it at low gain settings really doesn't give you good tonal control. Either you get Less High end with little mid and low end, or get high pitched noise. Totally not suited for anything other than solos.
Overall Impression — 4
Very easy to use, Very reliable... But useless musically. This is a beginners pedal... A professional musician, regradless of style would find this pedal appalling in comparison to either the pre-amps built into their amps, or just other better quality pedals in general. This pedal just reeks of the sound of a new guitar student picking up and a guitar an practice amp combo and sitting around all day playing palm-muted open E5 chords. Boss and DigiTech both make really reliable pedals that can survive a nuclear holocaust, and the only difference in them is their eq band... DigiTech usually are more rounded sound and Boss tends to be really high. If your looking for metal, rock or Grunge style distortion but can't afford an 1500-5000 grand tube amp, I'd suggest getting acutal tube pedals... Not tube screamers but other products such as the Tube King by Ibanez. They get much better tone, more like the tone you'd hear in your favorite metal or rock band without the several grand price tag of a stack.
Reliability & Durability — 10
Reliable as hell. You could throw it at a wall or pour soup all over it and it'd still keep on going. If I actually liked the sound of it, I'd probably use it without any backup pedals. The wiring and shell of the pedal are very durable. I've never heard of anybody having problems with this pedal functioning. In my experience, you can't beat a Boss for relibility and durability. That being said, I wouldn't recommend throwing them at the wall non-stop for a few hours because I'd think your arm would get sore before the pedal breaks. You need that arm to shred!
Ease of Use — 9
As with every other Boss stomp box, the DS-1 is very easy to use. You can be a total novice and Pick it up and easily figure out the ropes of the pedal. Very easy to adjust settings and how to turn it off and on. Changing the battery is easy to do. Input and output are clearly labeled, as are the tonal controls. Simple to understand, and easy to adjust. The manual provides a few hints on general tones, but you'd probably figure them out before you'd think to look at the manual because it's so darn easy.