I use it primarily for tethering, which is important to me. Also to use Skype on 3G, but not often.
I've added some of the themes and UI tweaks, app monitors etc, but only since I figured that if I was going to deal with jailbreaking the phone, I may as well get the most out of it. I could drop those in a second.
However, you're correct, there are often more hassles than advantages to jailbreaking, especially with the current v of iOS.
It used to be more useful, but now unless there's a dealbreaker for you (tethering and Wifi->3G in my case) than I honestly wouldn't recommend it.