Well, I just went to Radio Shack and I finally remembered to look for the Krypton 222 bulb. They had only one in stock ($1.29) and I looked at it closely, filament looked centered to me, so I bought it. I put it in my Splash-lite and yeah, it looked a little brighter than the old bulb, and the beam shape was different but still awful. The brightness difference wasn't all that obviously useful, either--maybe the beam had more bright parts or something. I put the old bulb back figuring substantially more runtime was probably more useful than some not-that-big-a-deal extra brightness. Then for kicks I compared the old bulb with my CMG Ultra-G, both for direct illumination (nearby target) and total output (bounce light off white ceiling), and to my surprise they were about the same. I put the krypton bulb back in and compared again, and its total output was much higher than the CMG. Of course, even with the stock bulb in the Tekna, the CMG has a huge advantage in runtime. I weighed both with a postage scale and the Tekna is somewhat lighter. The Tekna is somewhat more waterproof. Total size is roughly the same. Cost is about the same.
I concluded that except for the weight and waterproofness advantages, the CMG makes the Tekna with the stock bulb pretty much obsolete. So I left the krypton bulb in the Tekna just to give the Tekna some reason for existence. It really is a nice little light despite its low efficiency. However, to bring it more up to date, I still want to mod the screw-base bulb with an LED. The CR123 should run a resistored yellow LED just fine for a very long time, or I might try direct driving an R2H Luxeon with it. Other possible option is to try modding with a small bi-pin halogen bulb like a Minimag-style bulb. That should get more brightness and maybe a cleaner beam.