I built up a new set of 240's and upgraded the ratchet. While I've never ridden the "standard" 240 hub I will say, that this is without a doubt, a worthwhile upgrade. Anytime that you can increase engagement while simultaneosly dropping weight, its a no brainer. As far as durability, I have no reason to question the durability of anything in DT hub. They're proven by thousands of people to be a light, durable hub.
As for a comparison to other hubs that I currently own... I have a set of Kings, which definitely do engage quicker, However, its not all that noticable on the bike. I have a set of new XTR hubs laying around that "feel" like the engagement is the same... but I havent ridden those.
I dunno... I've got nothing to say but good things and I think you should definitely do this upgrade. Its what $30 or so for the upgraded ratchet? small price to pay for anything on a bike, let alone better engagement. better engagement usually means a new hub/wheel. You've got a unique opportunity to make a serious upgrade on the cheap. Doo it!