Good fork for 456 inbred

[Furberger]

I have an On One Inbred 456 - designed for a long travel fork. I'm Currently running an 07 All Mountain One on the front wound down to 140mm of travel. I'm pretty happy with the fork. Its not too heavy, the travel is good and you can lock it down for climbing (thought it would be a gimmick but really useful) but I find it a bit flexible for my riding, the front feeling a bit vague through singletrack.

Long travel - Low weight - Stiff - Pick any 2 I guess.....

I'm running a conventional QR axle and whilst the thought of shelling out for a new front wheel isn't appealing, I'd consider a 20mm if it makes that much difference to the tracking.

I've been a fan of Marzocchi since the Z1 launched but realise the game may have moved on a bit since then.....

I want something with less travel thats stiffer but at a similar weight and retaining the lock down feature.

Any suggestions?

[Beyond Rational]

A fox fork with the QR15 system? Vanilla or Float, 140mm travel, complete setup only adds a tiny bit of extra weight but 25% (apparently) greater rigidity.