It depends upon the individual betta whether or not they like it. Here's a recent thread with other user experiences as well as important notes about safety:
There is a danger the wire may hurt or kill a fish (no joke) so you should take precautions when using hammocks. The thread I've linked to goes into this in detail.
I have a hammock in my tank that I've gooed up with aq sealant as a precaution. Flambé seems to like it, but not as much as other bettas. This of course could be because I keep changing his tank around and there's so much new stuff to explore, lol :D