My brother and I are both looking for single stack carry pistols, and we both love the Sig Sauer P938.

There's so many choices at a wide range of prices!

He liked the Blackwood model and I found it for $680 shipped.

Is there anything I need to know about the different variations or are they pretty much just cosmetic differences?

Pretty much cosmetic and different grips.

P938 SAS

They are great little carry pieces.  I have two (Scorpion and Spartan), my DIL and several friends have them.  Maybe a bit heavier than a shield but has a great feel to it.  Pick the one you like.  

The price of the Spartan model has taken a huge jump this year.  Yikes!

I have a Nightmare and it has few sharp edges and grips are sharp too

I'm wearing a 938 "extreme" right now.

1)ignore the names and gimic looks
2) pick one with night sights. 
3)buy extended magazines, carry extended mags, stick flush fits in safe and forget about them. unless you really really really need the extra .75 in to fit in your speedo. 
4)shoot the shit out of them and enjoy

best single stack 9mm on the market imho. Shoots like a full size (with the extended mags) and carries in anything short of a speedo. 

Im a lazy carrier, mine rides in a remora iwb with an extended mag in gun, and one more in my pocket propped up by my phone to keep it orientated correctly. I shot my flush fits ONCE and stuffed them in the back of the safe. Won't be going back to them. 

Why the "extreme"? Because someone put it on layaway, and a gun store lackey accedentally computer logged it as sold and transferred. Buyer back out, the gun store was forced to sell it at a used price because of the transfer on the record. So I got a brand new gun (msrp'd near 800)for 600 bucks. Only requirement for me were the night sights and ambi safety (in lefty). Sure the "extreme" looks cool, but she is sexy because she shoots better

That has to be the most overused phrase on the interwebz.
The full size pistols must shoot like rifles in comparison.

They do shoot rather well.  Mine shoots nearly as soft as my PPQ and is really, really accurate in my hands.

The PPQ is known for being snappier than some others in it's class, but you get the idea.

Highly recommend the 938.

(Extreme model as well, but I did have the frame cerakoted.)

Installed aluminum trigger and slightly lighter hammer spring.  Much improved trigger.

Pick whatever 938 you like but be sure to get the Hogue wrap around rubber grip. Makes a huge difference in handling.

I have the extreame model as well but mine is a .380.  I like the smaller mag in mine when I pocket carry.

*shrug* try it sometime. But as the post you quoted said ...

In
My
Humble
Opinion

i carry mine daily, shoot it every range trip. Draw your on conclusions. I am just but a data point. 

The SAS melt job is nice but most CCW pistols don't to that extreme degree. And for pocket carry the idea that pulling the gun up and out means the back of the slide is the #1 snagger, with hammer and sights, an obliquely angled one like the LCP would be better. I gave it no further thought - if I am in a fast draw competition for my life with someone in public it was a total failure up front.

Some carry the 938 as a pocket gun, it's just barely over the line for me. In that role I bought a smaller .380. And the SIG in .380 is the P238, which is smaller and it is different because of that. It's not a 9mm with .380 loading, the 938 isn't a .380 in 9. Even the extractor is different.

New metal triggers are on the market but they aren't lego/plugnplay. And keep in mind the 938 mag is not easy to load at all. You do need a mag loader to shoot extensively at the range. I carry the flat mag for deeper concealment and as a back up, I wear size Large Gloves but I manage it. Shoot it a lot first then decide. Mags are not cheap, are well made, and are plentiful enough. It's a CCW type gun so a footlocker full isn't needed.

As for color, which part is shiny, grips,etc. it goes to impressing yourself, really. I got an Extreme with G10. Properly carried nobody sees it - so I can't impress nobody but myself. Let that be a guideline and what others think won't intrude, I'm not asking their opinion anyway. And those who need to express it? They just outed their issue real quick. If it's cosmetic, that is beauty in the eye of the beholder only. More than that it's an ego exercise on their part.

Pick what you like and ignore us. Your better choice is to look at the website and decide.

I have the extreme 938.  I find the grips not as "grabby" as I'd hoped.  They are definitely rough, but hard, therefore do not stick to my hand well.  A softer rubber grip would be superior, I believe.

^^^this^^^

We sell quite a few of them at my range. I am a big fan. For such a small gun they are very easy to shoot.

I owned a cw9 before the glock43 shield,and the 938 came out but have shot all 4 a lot. I think the sig is the best shooting one of the bunch.