I'll not get in to a proper review - I'm no selfbuilt; not even close - and have only had the module a day, so certainly cannot comment on reliability and longevity(!) However, since my last post, I did find a dealer with the D cell version in the UK, ordered one and received it. I'll just give you my first impressions.
Bar deciding whether to set the TLE-310M EX for one mode or three modes, installation was - not surprisingly - identical to that of my original, single mode, XR-E equipped Terralux TLE-300. During installation, the top of the module is almost flush with the top of the head, so it rather fiddly to really tighten down the module without your fingers slipping and smearing the optics. Other than that it is all pretty simple.
Screw the head all the way down; unscrew the bezel and remove along with the lens; remove the bulb and collar; screw in the Terralux module - it screws straight on to the threaded end of the bulb holder, so the bulb retention collar isn't used; gently screw the head back up until it meets the bottom of the module; drop the supplied o-ring inside the bezel, behind the lens; screw the bezel back on. Done.
When I was happy to carry large lights, I still didn't really want to carry anything larger than a 3D, and these days, I don't carry anything larger than a 2D, other than a Mag623 (and that's not really a torch that I would carry on a day to day basis). As such, I have installed the TLE-310M EX on to 2D Maglite that I can then use with either a mdocod 6AA to 2D battery pack, or with a couple of li-ion cells.
In comparison to the TLE-300, the new module is a bit brighter. Not hugely so, but then the accepted rule of thumb is that you need four times the lumens for double the perceived brightness. If we assume that the three XR-Es gave 600 lumens, the 1000 claimed lumens of the new module isn't even double the lumen count, so we couldn't expect it to be lot, lot brighter.
More importantly, the output is a lot whiter - my TLE-300 is only whitish in the very centre of the beam, with a very large corona that is a very noticeable blue/violet tint. There is no blue tint with the TLE-310M EX.
The hotspot at the very centre of the beam is around the same size on each I guess, but the new module's corona is smaller/tighter than the TLE-300. However, while you have that larger corona with the TLE-300, it has that weird, spiky pattern that they were notorious for. The beam pattern of the TLE-310M EX is pretty much round as far as the hotspot and corona are concerned, other than when used at extremely short distances. The very edges of the spill area do exhibit something of a lobe pattern from the three emitters. Speaking of which, the spill area of the TLE-310M EXs beam pattern is noticeably brighter than that of the TLE-300.
I've not taken the new module apart (I have the TLE-300), but the simple fact of it being encased rather than having open sides, makes it look more substantial and better built. However, the open build of the TLE-300 may have assisted with cooling.
On top of that, you then have the convenience of having multiple power levels, while having the option of a single mode if you prefer.
All told, I much prefer this version over the original TLE-300.
