Just got my old (1st-year reissue; '93 I think) Tube Screamer TS9 back from its second switch repair.
It stopped working mid-gig a few months back and I figured that I would just replace it with something (I thought) cooler.
I bought a Plush Cerberus Tri-mode Overdrive, which sounded great at the store. Well, it sounded great at home and it sounded great live - but a different great each time. Try as I might, I couldn't get the thing dialed in consistently so I was continually bending over to tweak it. It's got a lot of great sounds in there.
I generally set up my TS9 for a lighter overdrive which complements my dirtier Super Overdrive nicely. Could NOT achieve that same mid-hump tone with the Cerberus.
Finally, I broke down and had my TS9 repaired. It needed a bit of work besides the switch, so I took it to a repair guy. $30 later, and I placed it back on the board, set my controls the way I like 'em, and voila! There was my sound!
Cerberus is going on Craigslist. And the new Rat that I bought. Sometimes, sticking with the things you know, instead of variety, is the true spice of life. :)