I would go with the FX for many reasons, here are a couple of reasons why...Accuracy, power, modularity, high capacity magazines, adjustability and ease of tuning. The trigger isn’t the best but better than the SK-19.
A couple of other things that aren’t brought up nearly as often when trying to decide if FX is right for you is access to information. Because the Impact is one of the most popular air guns in the world, there are a million videos, schematics, pictures, podcasts, articles and other forms of information all over the web. Not to mention, Ernest is a member here and will answer your questions, if not, heavy impact, Edosan, Nervoustrig or someone else familiar with the Impact will. When you need help with a problem, tuning or fixing your air gun, access to quick information is of utmost importance and often overlooked by potential buyers. When you have a problem and need help fast, ask your question here on AGN & because it’s an FX, you’ll get an answer fast!
It’s also very nice to be able to customize and upgrade your gun very easily. It’s not chance or coincidence that the Impact is always being talked about here on AGN, it’s because so many people have and love them.
Stoti