Well, they ARE cheap... There's probably been enough talk around here about cheap vs. expensive and bad vs. good, but what the hell.
I just did some location work yesterday with my classical guitar trio and was really glad I brought along my 180s. Cheap mics on guitars in the $5,000- $10,000 range. Who'd have thought... The bottom line is whether or not they do what you need them to do.
Sorry, I bought mine specifically for plucked instruments so I don't know how good they are on other sources. The cardiod capsules seem to have a pretty pronounced proximity effect which might work to your advantage in getting a beefier sound. For what I was doing, I preferred the sound of the omnis about a foot away from the 12th fret of the instrument. The level of noise was acceptable - a bit more than
my AT4041 and significantly less than my Naiants - and the sound was more flattering than any of the above, to the extent that a wished I had picked up another pair.
If you're looking for something comparable, you might check out the SE1s. Again, my experience with these has been on classical guitar and vihuela (like a lute with a guitar-shaped body). The SE held its own with mics costing many times more, although the mic that we ended up settling on was a (60s?)vintage AKG 414. In any case, everyone in the studio was shocked at how well the SE stood up to the other mics we had auditioned.
Don't rule out your cheapo 180s just because someone has taken the time to point out the fact that they're not Neumanns. Mess with placement, play with the switches, swap out the capsules, try them out on different sources and in different spaces and you'll probably find a use for them.