I can understand that spending over $80 to mod a head that only cost around $60 in the first place doesn't seem to make much sense, but what you get is a true eye opener.
I really love the Aleph lights. Among those are the ones equipped with the 27mm reflectors. Although these are REAL performers, I wouldn't go beating around in the bush with one. If you need a really tough goto light with lots of heft, the KL3 is tough to beat. It has lots of mass for handling the heat and it's buck converter allows it to run on two or three cells.
I recently had a customer email me about one of the KL3s that I did for him. It was modified with a TWOK luxeon and the converter was ramped up to about 1.3A. Of the five that I did for him, ALL of them hit at least 12,000 lux at 50cm.
My favorite KL3 mod is to add the nice T bin luxeon and reflector, but leave the bias at the stock level. This results in a very bright light that will run for a LONG time. Heat is a non issue and the light is tough.
You could, of course, opt for the drop in unit, but the ability to get the heat out concerns me. I don't know how well the drop in would fare over time in long term use. On the other hand, at $30, it's a pretty compelling alternative.
I suppose this is as good a place as any to address the price of the mod, since it's been brought up. I charge $81 to do the mod. $5 of that is for shipping. What the other $76 gets you is a premium binned T flux luxeon and a McR27 reflector that is modified to fit into the KL3.
The KL3 is a bear to get apart and even worse to put back together again. After all is apart and modifications are done, I still need to modify the reflector on a lathe. Although that sounds like a simple process, it is tedious. I've had to rig a vacuum system to keep the chips away from the surface of the reflector, as it is very delicate. Of every 5 reflectors that I modify, 1 or 2 are rendered unsellable due to a rogue bit of aluminum. I also have to fabricate a spacer to position the reflector within the KL3.
The point is that the KL3 mod is about the most difficult mod that I do regularly. It's expensive, but you get what you pay for. You just have to keep in mind that the Luxeons run about $16 each and the reflector is about $14 (not to mention the ones that get screwed up), with another few bucks in the spacer, o-ring, epoxy, resistors, etc.
Geez, I need to stop thinking about this. I'm starting to want to raise my prices.
Well, here's a couple of pics...
The beam shot was taken about 20' from a white wall. The Luxeon was a T bin Lux III running at just over 800mA.