There are other forums out there, but frankly some of them get really annoying to interact on. Chowhound has the same question asked over and over and over and has tons of users and traffic (good and bad). In each Chow forum there are the equivalent of ham radio operators dispatching advice as soon as a post pops up so discussions often end up with the same people talking about the same thing. With that said, the people on the cookwkare portion of the form who contribute the most are also knife nuts, though I think only a few of them are on this board too and they might not be that active. Chowhound is a lot of home cook foodies with about half of the comments crap IMO. The interesting thing is that if you ask a knife question there it usually ends up talking about Japanese knives and sharpening stones. Not a bad thing.
eGullet was the standard but is becoming irrelevant in many of its forums (low traffic) except some regional ones, the alcohol boards, and the molecular gastronomy (probably a few others too). Their pedigree though, is excellent. Grant Achatz was posting on their boards when he was dreaming up Alinea and Nathan Myhrvold also used the forum extensively when putting together his tome, Modernist Cuisine. Chad Ward, a knife nut, also started his book on knives as an instructional on eGullet. But the moderators can be snobby and are crazy when it comes to new posts and merging them with older ones. And the head of it all (Fat Guy) seems like an a-hole IMO. eGullet also had a blow out of grand proportions a while back that makes the KnifeForum fiasco look like a picnic.
With that said, eGullet has a lot of industry users so you get more Chef recommendations and with Chow you get more home cook recs. Searching past posts on both is valuable at times. There are other forums too like ChefTalk which seems to be getting better and also geared to the pro cook. Cooks Illustrated has an older baking demographic it seems, and I find it mostly worthless.
The advice on this forum is usually spot on with little garbage advice to sort through, so it is more efficient I think. If you post here and don't get many replies it might be good to search the other forums too. The search function on most forums sucks though (including this one). Chow is pretty good though and eGullet recently upgraded their site, so it is now better.
Just some rambling.
k.