I have: Pelican 1xAAA/2XAA, UKE Mini Q40/Vectra, PT Rage/ Attitude/Aurora/EOS and a KBS 2D/3D. Sorry, don't have any SL, though I'd be happy to accept donations....
They are all very well made, but based on feel, appearance and design, Pelican are targeted towards industrial use, UKE towards diving and PT towards camping. KBS is clearly more towards industrial use where price is a big factor. I think the Pelis are beefier and more resistant to abuse, though UK's and PT's will certainly stand up to normal dropping, stepped on, etc. If you think your light might get run over by a warehouse Hi-Lo, get a Peli.
On the other hand, I think the PT's are nicer looking and more pocketable.
It seems UKE is biased towards runtime while PT and Peli are biased towards brightness.
Examples:
PT Rage (4AAA) runs 2.6 watt Xenon w/MOP reflector
UKE MiniQ40 (4AA) 2.1 watt Xenon w/ smooth reflector
PT Tec40 (4AA) 4 watt Halogen PR bulb.
Peli Mitylite (4AA) 3.6W Xenon module
Peli Stealthlite (4AA) 3.18w Xenon module
Peli 2600 Headsup (4AA) 4.5W Xenon module
Peli M10 (4C) 4.8 watt Xenon
PT Tec 400 (4C) 5.2 watt Halogen PR
UKE C4 (4C) 6.6 Watt Xenon
SL: 4AA ? watt Xenon, module
Xenon bulbs are more efficient than halogen while bulb/module reflectors catch more of the light (but cost a lot more to replace).
I have the miniQ40 and the Rage. The Rage is quite a bit smaller (due to using AAA's) but puts out about the same light, though smoother and with less throw due to the MOP reflector. It's very pocketable.