I’m inclined to share my experiences with the Saiga 12 as I’ve had my stripped farther than most and I’ve had enough time to gauge different aspects and functions with it.
If you’re used to a Benelli or even a nice 1100, this is not going to be a familiar gun to you. In fit, function, and controls it’s all AK baby! This is a good and bad thing. No one buys AK’s because of the ergonomics or controls, and likewise no one should expect better on the Saiga. This things are rough.
The so called Vodka Specials are so of an exaggeration imo. Yes, sometimes there are goofy things, grind marks on the barrel for instance, some barrels are glued and pressed into the receiver with the force of Thor’s hammer - others practically fall out with the cross pin removed.
My S12 started as a 24". It was the only one I could find locally before the ban scare. I picked it up, and immediately decided 24" would NOT do. These are not light guns by any means. I managed with very little online assistance to removed the barrel, cut it to 18.1", add two gas ports to the existing two for a total of four, drill all four out to 3/32", and re-thread the muzzle in it’s metric call out. I noted little online assistance because very few people strip these guns down to the bare receiver.
Note: IT WAS A BITCH TO GET THE BARREL BACK IN.
That said, I’ll never take one down that far again, just no thank you. There are shops that work on Saigas and I’d happily send to them for that work.
Note: There are a lot of shops that are doing Saiga work, I’d be aware of who you are asking to what and for how much. A lot of the “conversion” is extremely simple and if you can’t handle it, you might want to reconsider owning this gun.
Anyhow, by opening the now 4 gas ports to 3/32" I intentionally “over-gassed” my gun. I put quotes because a lot of the conventional knowledge on the Saiga-12 forum is very wrong. I was both to open up to 3/32 and to NEVER DO THAT!!! Well, I did and it works great. I am using the “Autoplug” a cool auto regulating gas system addition, there is nothing wrong with the manual versions though.
Note: Almost all of the “Saiga is unreliable” people tried using a stock gun with walmart bulk loads. By opening the ports I can shoot this stuff as well as 3" slugs. I do suggest the Tac-47 autoplug though only if you have enough gas to make light loads work. Lots of people get a gas plug and expect it to solve all their problems.
The main issue with the Saiga I have is reloads. While, yes, it is possible to swap in a 8 or 10 or 12 round mag or drum, it’s VERY VERY VERY difficult to do on a closed bolt!!
Note: VERY DIFFICULT at rest, I estimate near impossible under stress
The supporting issue is the there is no Last Round Bolt Hold Open on factory guns with aftermarket mags. There is an aftermarket LRBHO, but I’ve read poor reviews regarding install.
So what you have is a gun that is difficult to load on a close bolt, and does not have bolt hold open. Fantastic! Good idea Russia! 
I have come to the following conclusion on the Saiga-12… It’s best used for:
Three Gun / Race / Competition
If you’re going to really modify this gun, go for it. IMO, the only major modification needed is a mag-well. In fact, absolutely VITAL. While LRBHO is cool and all, the Rock And Lock method of putting the mag in sucks compared to just straight in - drop free. And it always will.
SBS
There is no better option for a breaching or short barreled semi-auto shot gun. A 12" that still has the ability to quickly load 5-12-20 fresh rounds is unbeatable (read: has a mag-well). This however requires custom piston work, custom gas port work, and this adds up. Don’t forget the tax stamp, and you’re into a $1500-2000+ SBS.
Fun Range Toy
If mag changes under pressure are not an issue, get one of those heavy and impractical 20 round drums and have a great time!
Having owned one for awhile now, I can not possible recommend it as a Personal or Home defense gun, it’s rough from the factory, and it’s finicky unless you really get into it. Even then without a good mag-well (which doesn’t really exist, TAC-47 has a nice looking on, but it’s $190 or so and I haven’t seen a single one reviewed yet). Mags are also an issue SGM, AGP, MD-Drums, Promag, Factory Izmesh, and others all work, only SGM appears to work with mag-wells. IMO this is not good enough, I need to know mags will be available for the gun and one company is not good enough for me.
If you put a mag well on it (newest Russian guns are getting the default), mags that are reliable, and put a lot of time into learning the gun, it’s probably great. I’m just not in love with it yet.
