I'm a regular user of all of the J&C films in 120, and the 100 and 200 in 4x5 and 8x10. The films are inexpensive and do have a few problems, but overall they're extremely capable films if you understand their strengths and weaknesses.
For the 100 speed film, the greatest weakness is the paper backing on the 120 rolls. Plain and simple: It sucks. The paper's cheap, there's no tape at the end, it's not really reliable for use in "red window" cameras, and it tends to end up loose when you're done with the roll. But if you use it in a camera without a red window and load/unload in dim light, you'll be fine. They include a plastic holder for the film, so once you've got it in the holder it's light-tight.
The other big issue with the 100 speed film is the softness of the emulsion. When it's wet, it's easily scratched by a fingernail or by the corner of a sheet of film. You must handle it gently, and using a hardening fixer isn't a bad idea.
There have been numerous reports of pinholes and other emulsion imperfections with this film, but after shooting through a whole bunch of it I have yet to see these problems first hand. Perhaps I do something in my processing that's stopping the holes from forming, or perhaps I've just been lucky. Regardless, I've been quite satisfied with the film and it's dirt cheap. (I develop it exclusively in Pyrocat-HD these days, as the negatives are just amazing.)
The 200 speed film is similar to a lot of other films on the market. Whether it's exactly the same as Forte 200 or a very close relative, it's got the same quirks as Forte film. The roll film base is very curly; make sure you weigh it down when you hang it to dry. Again, I've not had any emulsion imprefections with this film. I like the grain and tonality of this film a lot (I shoot it at 125), and the price is very good. It's not quite as soft as the J&C 100, but it still requires careful handling when wet.
My favorite film remains Efke 100, but both of the films mentioned above have been very good for me and I do use them a lot. They're much cheaper than the Efke, and since I'm only shooting for myself I'm willing to take the chance that I might get a bad spot on a shot from time to time. (Anything that I consider important enough to keep, I'll shoot a 2nd frame.)
Given the price, you might as well try them out. You never know if they're right for you without trying them.