I was an early adopter and I'm still a firm believer in male chastity devices. I have the CB2000, CB3000, CB6000, and several other devices, but the one I use the most is the Birdlocked (because the flexible material makes it more comfortable).
My wife and I play with chastity more than any other fetish, and I enjoy this play quite a lot because I consider it the basis for control which can be used to force me to comply with other often humiliating predicaments that interest me...like being sissified, queening, sissymaid, cuckolding, domestic discpline, the cage, strapon, etc.
Practically speaking, its not very comfortable (nor hygenic) to wear a chastity device for more than a few days at a time (despite what anyone might say)... and I wouldn't want to, but the threat of having to is always interesting. As long as there are frequent breaks, it can be used as a full-time tool. One of the great things about chastity is that it engages the male full-time with a constant reminder of his fetish and her authority, while the female keyholder doesn't need to dedicate much more time to him other than when the device goes on and when it comes off, if she doesn't want to...however, it's always better if she at least verbally teases him on a constant basis if possible.
I also find the process of "milking" to be very erotic. Milking is basically masturbation which can be done with or (more often) without pleasure to ejaculate the male. We never really implement milking in our chastity play, but it's a welcome idea to explore. It can even be done the chastity device on (through prostate massage), but more practically with the device off. There are lots of ways to make it as exciting or dry and non-stimulating as the administering female authority desires.