I used Fission for quite sometime, and rarely had any problems at all. I decided to make the switch to Liberty 1.5. I've been using 1.5 for about a week. The other day while using Google Voice, the phone locked up and powered off. It turned right back on, and I was on my way. Today, it did the exact same thing, except it won't do anything now. I've tried booting into Recovery, and it won't go. It will occasionally power on, but it'll go straight to a blank screen (you can see the backlight, but nothing else). I can't even get into bootloader.
Either way, I'm not putting the blame completely on Liberty because it could've been anything, and the simple fact that it happened twice while in the same application, Google Voice.
I'm just making people aware that ROM's, while they are very beneficial, can also damage your device. The chances are slim if you know what you're doing, but there is always the small possibility that you will brick your device, and that was my reality tonight.
I'm not depressed. In fact, I don't care much, and when my new device comes in, I'll probably be back on Liberty, but the fact of the matter is that I'll think twice about putting any ROM on now.