Picked one up yesterday at GC. Also tried out the Delta Labs Tube Overdrive, but after playing them in the store for a while I found the MXR was a little more versitle (but the Delta Lab sounded pretty decent too).
In case anyone wants to know what they sound like compared to a TS9, I A/B'd the MXR and my stock TS9 last night and tried to get the same general settings from each.
The TS9 is a lot more natural sounding, which IMO lends its self great for a boost for solos. The MXR is a little more noticable when you kick it on.
The MXR has a bit more gain and also a bit more contol over the tone knob than the TS9. The MXR can also be pushed to a kinda-sorta fuzzy distortion tone, that the TS9 can't really do.
All in all, it's a really cool pedal, and worth the price! It's not quite as smooth sounding as the TS9 so if you're looking for something to replace one the MXR would not be it. But for something a little different, I'd say it's a cool piece of gear.
