I am borrowing a 100mm fork to try on on the Karate Monkey for now. I have a set-back seatpost, 60mm stem, and 32" riser bars on it, so it's certainly a frankenbike at this point. I had a Vassago Jabberwocky for a little while and I could not stand something about it. I had the 16" frame, which had a 600mm ETT, which is what most 17-18 inch "medium" frames have. the KM has a much shorter ETT. I don't know if it was the longer ETT or the longer CS that I hated about the Jabber, but it rode like ass.
I could potentially put a 120mm fork on the KM but that would be pushing it. its' designed for a 80mm, so 100mm is fine. the HA is relatively steep, nothing I can do about that other than getting a new bike.
I work in the industry so I have only a few bikes that I can get a decent price on- Diamondback, GT, Cannondale, Surly (maybe), and that German Ghost brand, which I have not seen yet. I would have to sell my KM to afford a new bike, so I don't want to sell it and regret it.