We have been using Errbit for about six months. We are reasonably happy with it. On the plus side, it does the job; that is, it allows me to do my job. The UI is reasonably clean, and it reports every exception to our Campfire room.

On the minus side, Errbit is somewhat buggy, and very slow. If it gets any load at all (say, above 2-3 exceptions per second), it becomes near-unresponsive. A casual look at what it's doing seems to indicate MongoDB traffic. We are running Errbit on a small VM, but the slowness is way beyond what can be explained by the VM. So on the rare occasion we get an exception storm it's pretty much impossible to access Errbit.

It's also terrible at merging identical exceptions. Not sure why, haven't look at the code, not bothered enough to do so.

The origins of Squash predate Errbit. In addition, Squash is laser-focused on solving a specific problem, the signal-to-noise ratio in dealing with exceptions. The idea is get the bugs assigned or fixed as soon as possible, and bother as few people as possible.