I got this non-budget flashlight on Ebay for only $26.91 including shipping, and it performs even better than I expected. So well on AA that I waited to get a second example before taking one apart to convert it for 14500.
Lenser always on the left, UltraOK SK-68 on the right.
Zoomed in:
I am not sure why it does not match the throw. This is a large lensed SK-68. The apertures are similar, but the Lenser seems to have both zones a bit out of focus. The Lenser has what appears to me to be an XP-G2. The SK-68 of course has an XP-E or XR-E. The larger size LED contributes to the shorter throw, and probably also to the greater overall light output.
SK-68 zoomed out to match the Lenser:
Between the driver and the optics, it gets a lot more light from an Eneloop in the same state of charge.
Zoomed out:
The Lenser has more flood. This may only be because large lensed SK-68s don’t zoom the lens all the way back to the pill.
And the Lenser zoomed in to match the SK-68:
Again, the Lenser puts out more light. Perhaps the difference is less than zoomed in.
What I expected is that, because of the two zoned Fresnel-like optics, it would put more light into the spot, but have the same throw. More light seems to come as the cost of less throw. But, otherwise, it does seem more efficient.
Tail current is 1.13 A for my first example and 1.30 for the second, with an Eneloop charged at 1.45 V. At 1.28 V, the currents are 0.80 A and 0.97 A. It is not always the case with boost drivers that the input current increases with voltage.
Of course the finish is also better. The styling is a matter of opinion. I think I like the Lenser shape better, for these currents, but neither compares with the Smiling Shark SS-5039 or the Yezl t9.
Later, I found that the stock drivers do not take lithium ion cells. They put out light but are damaged by them.
Deducting one star for the price, I give it four stars. Light output is good. It can put nearly all of the LED’s output into the sport. The build is excellent. The star is copper and probably direct thermal. It has a good LED and a good boost driver. The beam shape is good at both flood and throw, and also in between. I like the forward clicky switch. As others have commented, the switch has a nice solid feel.