I have quite a bit of the Brothread (bought from Amazon) and the price is very good. I've not had any significant problems with it, but overall I like the results I get with the Floriani thread better. So far those are the only two I've used.
I think the main thing for me is the colors don't seem quite as "rich" as the floriani, however sometimes having something with just a tad less sheen is fine. I do think a person would be hard pressed to tell which colors on the embroidery where which thread.
I'm sewing on a Babylock Destiny - and this machine seems very un-particular about thread. Most of the problems I've had are due to the thread coming off the spool and getting caught somewhere - not in the machine making a stitch.