Eesh, sorry for such a delayed response -- haven't been spending a ton of time online lately so just saw my page. I'm assuming you made your decision already, but IMO so far that adjuster is the best 10% I've ever spent.
My personal experience leads me to somewhat disagree with
@Duke03 -- for us, part of the reason it worked well was because we hired them right away. They brought in their own team of people to develop our own rebuild cost, in the format the insurer uses (over 100pp, room by room, inch by inch). They brought in a relo team that took care of the apartment lease and rental furniture for us and billed the insurer directly for it (they do not take a fee from us for this part). They also brought in their own inventory guy who took all the time to inventory everything that was destroyed -- and after seeing his more-than-1000-line spreadsheet, and dealing the amount of work it's been for us just to get him the information he needed to flesh out a small part of that list, I can honestly say that there's no way we would have been even half as detailed. They've also given us important guidance along the way -- like what our rebuild contract needs to say so we get paid on the front end (our contractor is great but does not "speak" insurer), or not to throw out any of the inventoried goods until the insurer approves us to do so, etc.
In the end, I do think they will get us a higher recovery than we are paying them in fees -- but even if not, they've saved us weeks' worth of work and an unlimited amount of stress of learning the whole insurance process. I mean, sure, I could learn that if I wanted. But we have two jobs and two kids and, oh yeah, we'd really really like to get our house rebuilt so we can move back in, so my decision fatigue level is pretty high without adding the insurance stuff onto it Basically, I don't know what I don't know, but I do know that what I don't know can cost me a ton of $$$, so hiring someone who knows what I don't know lifts a giant mental weight so I can go off to do things I enjoy more.
I also think there is an intangible in dealing with the insurer when they know you've hired a reputable adjuster. We received a full policy-limits payout for the rebuild within 3 months of the fire. A huge part of it is that having guys who know the insurer's forms and computer system saves time -- and believe me, that's a huge deal when you're looking at 9-12 months to rebuild AFTER you get the insurance approval/$$ to start. But I also think there's a sort of recognition that there's no point in playing hardball or trying to get away with stuff, because we're working with someone who knows the tricks. (I don't mean the insurer is being illegal or immoral; we've actually had a fantastic experience so far. It's more that our experience has been SO much faster and smoother than the experience of others who dealt with the same insurer without an adjuster, and I suspect part of it is just that when it's a close call, the insurer is going to be less inclined to be aggressive with us than with someone else)
Am I happy about having to spend what's probably going to be close to $150K? Fuck no. But even if their work doesn't get us the full $150K extra from the insurer, I'd still do it again in a heartbeat. Dealing with a major fire and rebuild while juggling kids and jobs is stressful enough, both in terms of practical things and in terms of weird emotions that hit at massively inconvenient times. So if I can outsource yet another major source of stress, and I have enough money in the bank not to have to worry whether the adjuster's work will fully pay for itself, why wouldn't I? Money is there to make our lives better, and this is a problem I am absolutely fucking thrilled to be able to fix by throwing money at it.