Largest fixed I carry is a Steve Mullin fighter, 6" blade, 5" handle, D2 and canvas Micarta. Lovely blade, good balance, sharpened false edge clip point, rather lively int he hand, and with a few mods to the micarta (re-shaping to fit my hand personally), its one of the best medium fighters I've had. Carry it on my belt a lot, even urban environs a few times, although I would like to get a kydex concealment sheath made for it for such carries.
I'd like to gwt another Cold Steel Recon Scout for carrying when I go out shooting, hiking, wdoing ranch work. The Mullin is a fighter and not too suited to heavy utility, but the Recon Scout is a great utility tool, capable of handling heavy work, but still lively in the hand enough to be a fighter in an emergency.
Its not super-large, and doesnt weight a lot, is a versatile design with a versatile handle... I really liked the first one I had, need another.