Things I liked: This is one really good looking rifle. It is the first real pellet gun i have owned. My first BB gun was when I was 6 (nearly 70 years ago) and I have had one almost continuously since. But prior to this, my best one was a Daisy 880 that can shoot pellets but I always just used BBs. I am blown away at the quality of this weapon in comparison. I purchased it mostly for target shooting but probably will use it once in a while to get rid of pests. Many have said that the scope is poor. I have no basis for comparison as I never used one before. My old 22 never had one and neither did the M1 I shot in the army. My Daisy 880 came with one and after one look through it I simply trashed it. This one was my salvation for this rifle (see my comments below). I found the scope to be ok as long as I don't use the zoom. Zooming simply gives it tunnel vision. I really see no need for me to zoom so for my purposes this is not a big problem.
Things I would have changed: Very first thing would be the hard sights. Since I had never used a scope, I intended to continue and use the hard sights. In fact I never even considered any rifle that did not have hard sights. But I found that I could not zero in the hard sights on this rifle because the back sight would not adjust down far enough. Even with it cracked down completely my shots were consistently about 1.5" high when shooting from 25 yards. I also felt that the front and back sight combination was a bit too wide making sighting a bit difficult. I was about to return the weapon but decided first to try it with the scope. I was able to quickly zero the scope and my shots formed what for me is a pretty tight grouping (from 25 yards roughly 1.5" diameter, probably not good for most you reading this). The other thing I would try to change would be the weight. While i do not have a big issue with the weight, it does seem a bit high for a pellet gun. As I recall the M1 was around 10 pounds and considered to be rather heavy. Pellet gun is over 8 pounds approaching the M1 weight but of course not coming close in firepower or distant accuracy
What others should know: I have tried two different pellets so far. The first is Benjamin Discovery .22 Cal, 14.3 Grains, Hollowpoint and the second is JSB Diabolo Jumbo Exact Heavy. I bought the Benjamin as my "starter " pellet because it was less expensive and had a pretty good user rating. I bought the JSB because I found it to have a much better user rating although it was a bit more expensive. So far I have made three shot comparisons. In each case I shot 10 of each pellet from 25 yards then measured the XY coordinates and compared the means and standard deviations. In each case the the standard deviations were similar (meaning no difference in precision). However the JBS pellets hit consistently lower and a bit to the left, meaning I would need to adjust my scope a bit when using the JBS. I may try another pellet later but for now I will stay with the Benjamin Discover.
Things I liked: I bought this because I have a Walther PP my dad brought back from WW II. It has never been fired since he returned (1946) and I don't intend to change that. But I always wanted a BB pistol to plink with and this PPK/S looks nearly identical to the PP (which I have found was made in 1935 and was a Nazi officer's weapon). The gun shoots nicely and the action is realistic with the semi-automatic feature
Things I would have changed: The very first thing, since my concern is for it to look like the PP, would be to remove curvature at the bottom of the magazine. The PP has a flat protrusion on its magazine. Yes I know this is a PPK reproduction but I want it to be a PP reproduction. Beyond this personal want my one negative criticism is the accuracy. My pistol seems to spray the shots all over. Also the sights are not even close. You might as well ignore them and just point and pull. If the accuracy were a bit better, I would also criticize the velocity. At a reported 295 fps the gun seems to just be spitting the BBs out. However as inaccurate as it is there would really be no advantage to having a higher velocity.
What others should know: Unless like me you just want a Walther PPxx replica, there are bound to be much better BB pistols available