I didn't use this much initially, mainly because I really liked the spirit ally version of Bofur. However, I've been including it more often now and thought I'd give this dwarf some praise. First, his ability is great. He's the tactics version of Master of the Forge, who is also very useful. In a deck with a reasonable number of weapons, even 3x3 weapons, he has a good chance of grabbing one if you don't have any in hand. And, like Master of the Forge, he'll shuffle your deck even if he whiffs so he can bring that needed weapon up to the top for the next try.
Second, his stats are very, very good for a tactics ally -- even ignoring the various dwarven boosts that can benefit him. In a sphere that is notoriously light on willpower, his 2 stands out, and 2 attack is decent. That combination makes him great for quests that have both normal and battle quest stages. He won't be defending much, but there are plenty of ways to get that job done in tactics. And 3HP makes him very hardy, so treacheries that hit questing characters aren't a worry and he can soak up some archery damage if needed. I think his stats shouldn't be underestimated because once you've used his ability for a few rounds to arm up he can still make real contributions.
The only possible concern would be his 3 cost. This makes him not great if you're only running a single tactics hero, but otherwise compares favorably to other allies. Only Pippin gets you 2 willpower in tactics at a lower cost. There are a number of tactics allies with 2 attack for 2 cost, but they are typically only usable for that attack and don't have Bofur's versatility. And the aforementioned Master of the Forge costs 2 but is useless other than a single chump block if you're done using him for his ability.