Our Department was given a couple of these to "demo" before they came out on the market. They are not too bad for a small "officer tool". Forcible entry into windows, doors. Breaking windows. Shutting off utilities. But it is not a "universal", 1 tool does everything. There is no such tool. If you are looking for a small tool to take alot of "abuse", then this is it.
I have one and it's OK for tight spaces in structural collapses, trench rescue, etc.
I wouldn't use it as an officer's tool - we do better with 4-foot NY roof hooks.
For general USAR use, a 28-oz framing hammer and a regular wrecking bar are better - the hammer is a little easier to swing and the wrecking bar gives you more leverage for pulling nails, prying sandwiched lumber apart, removing cleats and gussets, etc.
We purchased one for each engine several months ago.
Being a slow department in terms of fires, we have had very limited chances to use it and we are still in the process of deciding how effective it will be. Some of the guys have been using it in place of the Halligan, but IMO, it will never replace the Halligan and will always be an adjunct or secondary tool too it.