So, I bought a TK30, after my Solarforce Masterpiece died (the seller is replacing it for me, though). The TK30 is essentially a TK40 that runs on 18650/16430 batteries instead of AAs, so, you can pick your power source, really.
Really, the things you pay for in expensive lights are reliability and user interface. So, hopefully it'll prove reliable, and here's a run-down on the interface:
It has three sets of two modes. That sounds confusing. Let me explain: When you're using the light, it has two modes, selected by loosing or tightening the head, same as with many other lights, including the PD30 and such. The thing is, there are three possible sets of outputs it'll use, which one can select from these:
1) 100 lumens / 600 lumens
2) strobe / 600 lumens
3) 40 lumens / 120 lumens
Actually, I made up the numbers for the last one - suffice to say that both outputs are low. So, I use set 1, which exactly what I wanted. tightening and loosening the head rapidly a few times switches mode sets. Is that clear? Probably not.
Anyway, it's a nice light, and I have no complaints so far.
So, compared to the Solarforce? Well, I have to say I liked the styling of the Masterpiece better. The chunky square knurling on the body is just so nice. Don't get me wrong, the Fenix is nice, too, but I just like the overall look and feel of the Solarforce better. Let me find some pictures:
The modes of the Fenix do suit me better, though. The Solarforce just cycles between low, medium, and high - I think from memory it comes on in high mode if it's been off for a few seconds, or something.
Anyway, they're both good