I have used a lot of their thread in the past because you just can't beat the price for the selection. After a little scuffle with them over customer service about a year ago I haven't ordered since though. They sort of said "if you're not happy with us then don't let the door hit ya on the way out..." for the most part. I think that kinda stinks.
As far as the fabric, in all fairness, I like it and have never had any issues. I actually really like their thread and was super bummed after my experience with them. Customer service is huge to me though so for future orders I'm spending a little more and buying Superior thread. They have been outstanding in that department.
I'd say if you're unsure try it and decide for yourself. Free shipping over $50 when purchasing online is a great enticement. I don't think there is anything wrong with their products.
Edited to add: No I don't think it compares to Superior or Aurifil or some of the higher end brands. It compares more to Coats and Clark thread in my opinion and I like Coats and Clark but my sewing machine doesn't!
If I had a choice between C&C and CT, even though they ticked me off I'd pick CT.
