Overall they are good. I'll be keeping mine, but there are a few things one should know before purchasing.
1. There is no Ataman USA or anything like that, but Pyramid Air is great! The have many parts you will need and they can do work on it also. I had them fix mine and it was cheap and easy.
2. They are made with a lot of little parts, like little springs, balls, pins (Be carefully taking them apart.)
3. They do not have any MOA tilt to their rails, so therefore, you will need a scope with a lot of elevation or will need to invest in an adjustable scope rings. Plus, the scope sits a little higher (on the M2R bullpup) than I like, with adjustable scope rings, I feel it is a little too high for my liking, so I have to go with low rings and a scope that has huge elevation adjustment range (SWFA with 120moa adjustment) to get it the way I like it.
4. Mine in .357 is very accurate. The .22 from are also very accurate. I heard some of the .30's weren't at a time, and some 25's also had some issues.
5. Mine did not come with any moderator attachments at the end, so you will have to invest in a one for $45 or so (if you buy a .357). Although, I believe that some of the other models have either a shroud, or some baffles, but mine does not. Dana said the bp15's shroud still had some bark to it, so he fitted it with a donnyfl.
6. The power in the models for pellets is are strong, but that makes them inefficient with air. Mine shoots a little too hot for JSB's and had to tune it down. It also actually shoots LIGHT slugs very well but it can't get the power to shoot heavy ones. It will never be a legal bigbore Large Game hunting rifle. Max slug power is around 150fpe or so.
7. Their 300 bar fill is also a blessing in disguise, Sure it is nice to have a gun with that extra capacity, but with an air tank you can only fill it rarely to full capacity. To keep it consistent most people go to only 250. Therefore, for example, if it says 14 for a shot count, only expect 1/2 that or 7 to 8 shots.
8. The regulator in the Atamans are AWESOME! In Mine I get crazy consistent shot strings. All seven shots (a full mag) is less than 10fpe, always! With UN-Sorted pellets! Never seen a better stock regulators in the gun. No need to up grade to a Huma.
9. My Model did not come with a bipod rail, or any other rails (besides the scope rail). It would have killed me to drill a rail into the beautiful wood, so I had to hire someone else to do it.
10. Some people say their price seems to be for the most part a little steep. I think I agree. For $1600, I wish the had the a moderator (or at least an attachment), 20moa rail tilt, forward cocking lever (instead of the back one), and a little less weight (in my opinion) but it is not bad. (The weight is not like a Hatsan or anything.) Edguns are at the same price point and have all these features. I feel there is no reason why they can't be a little cheaper. But, all-in-all they are at a GOOD rating, not Excellent, in my opinion.
Hope this Helps.