Olight M20 R5 Vs. M20 S2

I'm wondering what the difference between these two lights is in output (320 lumens v. 340), tint, runtimes, etc. I've seen the published numbers, but I'm interested in a more subjective view from someone who's seen both.

The runtimes on both lights are similar. I want to be able to get a long runtime at a low setting, which the R5 has. I've also seen variations on light color between different R5 units. Some run a little yellower than others; of course, most prefer white. Finally, why are the S2 models so difficult to get at good prices? In fact, the S2s run a bit scarce, period.

Any subjective reports would be great. Thanks!