What's the price range like?
This might be just me, but I've had some surprising results with some surprisingly cheap/shitty pedals, depending on what you're running it in to...
For example: I bought a used Metal Muff from Guitar Center for about, 60$ just as some pocket distortion to bring to school (Keep in mind that the standard amps at my school are Fender Devilles.. not the most metal amp in the world..). I tried the Metal Muff through my Axe Fx just to get a point of reference and it sounds like the steaming-est piece of shit I've ever heard, same with through my little Line 6 combo. That said, when I brought it to school and plugged it into that Fender, it sounded absolutely AWESOME and got me every metal tone I wanted (along with a bunch that I had no desire for, but I'm sure somebody would've liked somewhere lolol).
I've had similar experiences with a Boss Metalcore (also pretty inexpensive), but it ended up coming through sounding much less tubey than the Muff. Also has less knobs / tweakability (and no Top Boost, if you're into that kind of thing).
I'm not sure how much you should trust my opinion though considering I usually try to stay away from pedals hahahah. Also, I dont know what kind of other gear your friend has, and I've never played through a Carvin X60B.. the pedals I mentioned might sound like shit through his rig, I know they're definitely capable of not sounding great lol.
Just my 2¢, hope your friend finds something he likes