I'm disappointed with my SC52 (and previous H51w), it's a shelf queen.
- ZL likes to spec their 1.5v lights like other AA/sub-lumen competitors (47s, ET, TN) spec their 3v lights (eg QAA2-X and D25C-X).
- I knew the SC52 wouldn't hold a candle to the above 3v lights (with nearly the same specs across modes btw), but I did find it equally efficient (lm-hrs) with the competing 1.5v versions (QAAX and D25AX) in sample side-by-side output/runtime tests using both a light meter and stopwatch.
- What unpleasantly surprised me the most was how far off all the L modes are. As a low lumen/runtime junkie, I find I use 0.3 & 3 lms 80% of the time, and it's what I bought the SC52 for. I measure these to be ~0.08 and 1.5 lumens (1.0 on 14500s). At least it explains how ZL gets 2-3x the runtime as the competing lights at the "same" lumen levels.
- I realize low lumens are a very personal preference, and some like very dim sub-lumen modes, but to have three choices below 0.1 lms doesn't make sense to me, not to mention it's less than half the output of it's own sibling the H51w 0.2 mode. But this must be a "Goldie Locks" problem for just me, I guess.
- I'm not really a tint snob, but this my greenest XML light... out of almost a dozen.
- I like the volt meter with 14500s, but it's pretty useless with Eneloops, and the damn auto low voltage stepdown precludes the use one my favorite cells - the 3v lithium primary CRAA/14505.
- It's a little brighter than the competition, but you'll need equipment to be sure.
- I think the UI is great, but I'm not sure I'm sold on the idea of electronic switches yet. They add more complexity and yet another failure point (seen enough post, not just ZL) and is not user serviceable or field repairable/by-passable.
- I find the build quality very "nice" but refrain from saying "good" due to durability concerns (see above). Perhaps it's just me, but find it hard to trust a light when it's own manufacturer doesn't seem to (eg, warranty and customer service). That said, I'm sure these policies help it keep its price reasonably cheap, and that's a viable business model too.
- For the short time I did EDC the light the sharp edges around the clip and knurling on the tailcap chewed up a few jeans pockets. I dremeled and sanded the bad spots, but ended up put it on the shelf anyway.
It's actually an excellent light, but I guess its just that the company's marketing, warranty and CS policies, and low mode spacing, don't happen to agree with me.