I can’t speak for Glock or other brands chambered in .357 Sig but I can relate some of my experiences with Sig pistols. Please note the following is my OPINION or preference only.
I shoot a lot of .357 Sig in my P226, P229 and P239 pistols and have not had any wear or maintenance issues in any of them. I switched to the .357 Sig cartridge after years of using a .45 ACP for my carry round.
I researched the round and tested it before trusting it for carry and was quite pleased with my findings. It is an accurate, flat shooting, hard hitting round with tolerable recoil. Some loadings can produce a lot of muzzle flash but some do not. If you reload, using faster powder will usually produce less flash. As a reloader, I have very little experience with factory ammo so I may be mistaken but I would expect manufacturers producing defensive ammunition to use flash retardants in their powder. Does anyone know if that is the case?
Reloading the .357 Sig is a bit more demanding than a straight wall case but really no worse than any other bottleneck case. I think of it as the price you pay for loading a high performance round.
I found bonded bullets such as Gold Dot, XTP, etc are a must in this caliber. All other bullets (Sierra, Zero, Montana Gold, Berry, Xtreme, Rainier) fragment or otherwise come apart to different degrees and penetration suffers as a result.
I like the option of changing from .357 Sig to .40 S&W with a simple barrel change. The .40 cal magazines work fine with .357 Sig so you don’t need dedicated .357 Sig magazines although they are available.
I particularly like the P239 since, in addition to the .40/.357 swap, it can also be changed to 9MM by simply changing the barrel. Unlike the P239, the P229 and P226 require a top end change to switch from .40/.357 to 9MM. Sig sells caliber conversions which are complete top ends. I think I paid approx $300 for my last one with night sights.
All three of the models I have feel and point differently so I would suggest you try each BEFORE buying one. The P229 is slightly wider and has a more blocky feel than the P226 but I found it to be slightly easier to carry in a vehicle due to its slightly smaller profile.
After carrying a 1911 for many years, I found the slimmer P239 points best for me and is the easiest to carry. It doesn’t have the capacity of the larger pistols but I’ve always thought 8 rounds are adequate in a carry pistol.
All my Sigs are VERY accurate. To experiment, I did put BarSto barrels in some and had mixed results. The BarSto barrel made a noticeable difference in two and not so noticeable in another, which was already quite accurate.
I have never had any failures with my Sigs nor have I had to replace any parts yet. I don’t shoot thousands of rounds per week but I do shoot regularly and I do reload so I may shoot more than the average gun owner. I did have a leading problem in ALL of my Sig pistols when I loaded cast bullets in .40 S&W. I never did solve that issue. I tried a couple of different brands of cast bullets and had the same leading with all of them so I stopped using cast bullets in my Sigs. It was no big deal since I mostly shoot .357 Sig and load plated and jacketed bullets.
Grips make a HUGE difference in the way these Sigs feel and point so handle some before you buy if at all possible. Also, just because one style works well with one Sig model doesn’t necessarily mean you’ll like that style on other models. For example I love the Hogue G10 grips I put on my P226 pistols but that same grip style didn’t feel very good on the P229. I much prefer the stock grips on it. There are a number of grip choices available for Sig pistols and each style has a unique feel. Some grips can be a bit pricey so it pays to try them before you buy them if possible.
Sig offers regular and short return triggers (SRT). I have both types and have found them to be, in my opinion, mostly a matter of preference. The SRT offers a shorter reset. The SRT triggers are readily available and fairly easy to install.
Sig also offers a .22 conversion unit. I have one for P229. I’m kinda lukewarm on this .22 conversion. It works OK but I’m having trouble warming up to it. Just my personal preference I guess.
To sum it up, my experience with Sigs has been very positive. I like them. Mine have all been 100% reliable. I carry Sigs these days when I’m out and about.
It hasn’t always been that way. I carried 1911’s for 40 yr until I transitioned to the Sig platform. I still love my 1911’s and enjoy shooting them but I carry Sigs now. They suit my needs better these days. Your mileage may vary.
There are some very good deals to be had on red box Sigs. To the best of my knowledge, these are agency turn –ins which have been factory inspected and internally reconditioned for resale in red boxes rather than the normal blue, black or grey cases. They may show some carry wear or signs of use but are functionally perfect. I found some smoking Gunbroker deals on red box Sigs and was VERY pleased with what I received.
Sigs may cost a little more than some other brands but I feel it’s money well spent in the long run. I don’t see how anyone could go wrong with a Sig.
That’s my two cents. . . . . . . . . .