Thanks for the replies folks.
So the main difference is just throw/flood.
Is the Biscotti firmware on the SST20 similar to the 12 modes on the LH315D?
Also what SST20 driver would you recommend? From reading previous posts, I was thinking 7135x4 so as to not overheat.
But…
I wouldn’t be using it on high very often or for very long, mainly on middle setting, so should I go for the 7135x8?
It is the same, but on LH351D you need to do 20 clicks (in x*7135 is 10 clicks) to enter settings.
6*7135 could be a good compromise if you’re not going to use high mode for long.
SST-20 has a smaller LES (light emitting surface?) but apparently the CRI is even higher than the LH351D. LH351D in 2700k is a nice high CRI tint compared to Cree 3000k. Yet to own a torch with 2700K SST-20.
You may get a smaller hotspot with the smaller LED and it might heat up more on high mode.
7135*6 would probably be a good choice, comparing two XM-L2 S2+s the brightness looks similar to 7135*8 but it uses 700mA less and runs cooler.
I forgot about one thing - LH351D is much brighter. At 3A it puts out like 1200lm meanwhile high CRI SST20 just 720lm. And S2+ with LH351D comes with 5A driver for roughly 1800lm (and quite a lot of heat altough it is temperature regulated - it will reduce brightness to avoid overheating) output meanwhile SST20 one with 6x7135 driver will make just ~550lm (while staying relatively cool). Medium mode in the LH351D version should be about as bright as SST20 at full power! So we’re talking about two different flashlights from the brightness standpoint as well.
I was siding with the SST20 for more throw, but now that you say the LH315D is much brighter, I’m torn.
For reference, mainly I want it for walking my dog. I got a present of an olight I5T and use that on low (15 lumens), while it’s enough light(more floody in my inexpert opinion), I would prefer something with a little more throw.
Maybe the middle setting on the SST20 or LH315D would be more than enough for my needs, regardless of how bright?
Again, appreciate all the replies 
1200lm at 3A? And 1800lm at 5A?
I guess you took this data from the Texas_Ace test.
But he tested the cri70 version. Simon has the cri90 leds.
Looking at the maukka test of the cri90 version at 3A it is <1000lm, and at 5A <1300lm.
In addition, both tested LEDs are 5000k, and 2700k will significantly lower these lumens.
I’ve already ordered the Sofirn SC01 which is SST20 @4000k, so I would like something warmer to try out, the Convoy SST20 only has 2700k and not a 3500k option, whereas the the Convoy LH315D has the 3500k option. So maybe the 3500k would be a nicer beam…
Watch out for zeros!
Your CCTs are very cool 
Haha, rookie mistake, thanks for the heads up 
LH351D has two middle settings: 3% and 30. If those are accurate then it should put out 75lm at 3 and and about 600lm at 30%.
The SST20 version it’s more complicated due to multiple groups of different modes that can be selected. But if you’re going to choose 6x7135 driver (max 2,1A) the 10, 20 and 35% middle modes (available in diffrent groups) should net you 72lm, 145lm or 230lm respectively. Those will go higher by 20-25% if you are going to choose 8x7135 version of the driver.
Thanks very much phantom23. Those mid lumens suit me perfectly, I’d probably be mainly going for the 72lm, would you have a runtime in relation to those lumens?
What battery do you have?
“Throw” and “S2+” really shouldn’t be used in the same sentence. Tubelights are great for flood and intermediate range. You want throw, get a thrower. You’ll be happier that way.
That said, no one ever went wrong getting a ’351.
I did runtime and shoebox lumens testing with a 7135*8 2700k SST20 S2+
Here’s my estimate based on the data sheet and my 7135*8 example:
The SST20 with SMO is one of the throwier S2+ models and with the 2700k LED it’s one of the least efficient and IMO useful models. I like mine for the tint but don’t use it for much serious use as the beam is not very useful and the runtime is poor, even in comparison to other 7135*8/7135*6 models. I assume this inefficiency would transfer to 7135*6 models as well.
I have runtimes for a few different S2+ lights at the link below. The 7135*8 SST20 2700k is about as bright as the 7135*6 XP-L HI 5000k model but has about 60% of the runtime.
https://asatisfyingwasteoftime.wordpress.com/2020/11/22/convoy-s2-runtime-graphs/
I have a LH315 arriving in the next couple weeks so runtime for that should come soon.
The CSLNM1 S2+ models are very throwy for an 18650 tube light.
Just sharing on the LH351D…
I have S2+ LH351D 2700k, 3500k and 5000k.
I really love the 3500k a lot.
On the contrary, throw is relative. I like my D4v2’s XPL HI beam while the S2+ with sst20, 4000k is too throwy for me!
S2+ with the cslnm1.tg has just a slightly bigger hotspot than the D1 with XPL HI
Smaller reflectors usually exacerbate crappy beams. Piss-yellow coronas on Crees, nasty coronas with other chips.
Unless you really keep down the LED : reflector ratio as small as possible, that’s a given.
But with teenytiny chips and teeniertinier surface area, you’re cranking up the current density, killing efficiency.
Take one of those CSI-NY chips and stick it into a GT reflector, and you’ll get a crisp beam.
Big chip like a ’351 in a small S2+ (or FC11, or SC32pro, or whatever) reflector, and counterintuitively you get a pretty good beam, especially if the reflector’s OP and not SMO. Not much axial tint-shift to ruin it with a nasty corona. I’ve had pretty good beams overall.
There are not many complaints about color shiftin in the S2+.
‘Arlo’ is not looking for a thrower but simply more throw than Olight I5T at 19lm setting.
If you have true 3000mAh battery, with 6x7135 driver (2,1A) at 10% setting we’re talking about 10 hours of runtime, maybe even slightly more.
One more thing - Simon from Convoy (active on this forum as well) is quite elastic when it comes to flashlight configuration. You may ask him to install LH351D emitter instead of SST20 as it’s more efficient and you like the modes of the SST20 original driver.
