My friend bought some Ultrafine Xtreme 100 in 120 size, and we tested it a little bit in different developers. Overall the results were terrible. Really crappy tones and worse, the backing paper patterns (little circles and such) bled through onto the image! Everything shot with this stuff was crap. I've seen similar issues with some of the cheap films made in China.
I also a couple of years ago shot the rebranded XP2 they sold and it was scratched beyond belief. Like, big honking scratches that made the negatives unusable across 1/3 of the roll or so. I checked everything and it was only those rolls so I am 100% certain it was their bulk-loading or whatever.
I would stay away, personally.
Edit: I did some Googling and I guess it's well documented that the 120 version of the 100 speed is a dog. So YMMV with other products.