I've got a pair of Charvels with Kahlers, and I know Dave does, too, so there's gonna be some feedback here, mos def.
I love the feel and adjustability of Kahlers, they're my favorite trem, feel-wise.
The sustain issue is probably a placebo, but it might be due to the construction, Kahlers are made from Brass, with (IIRC) Steel screws, and Brass is heavy, but not quite as resonant as hardened steel, like the OFRs. (In keeping with your swiss army knife comment, though, Kahler does sell parts for their trems in Brass, Steel, and some parts aluminum, but expect to pay a premium.)
The only Lock-able Kahlers are Hybrids (and the X-Trem), unless the 2300 series has been updated with the set screw, so make sure you check that.
Kahlers are notorious for falling out of tune after abuse, not only for the roller issue, but also because they're only a single-locking design, and the strings are only held to the trem by their own tension. When you dive them, the strings can come loose from the claws that hold them, and when you return to pitch, they might not seat properly again. With my FR guitars, I usually don't have to retune after I record a track, but the Kahlers, I almost always do. I'm sure there's a way to rectify that, but honestly, I haven't put the effort into it to learn how, as my main players have Floyd Roses, and the Kahlers have been relegated to practice axes.
If you like the adjustability of the Kahler but don't like the stability issues, there is a Kahler fixed bridge, but that seems like a cop-out to me, why get a trem-styled unit if it's not a trem. I'm not trying to dissuade you from Kahlers, because they're extremely cool and look awesome, to boot, I'm just trying to paint the most negative aspect of them in an awful light, so your experience will be better