One of my mates got one recently and is really pleased with it, aesthetically not my cup of tea but the build quality is decent. Supposedly they are on par with the TM M870 in terms of performance, but I have no idea if this is correct. It's a shame Airsoft gun reviews tend to either be affiliated with a shop or consist of "I got a gun and a box and it fires BBs, would give a 10/10 without bothering to use in a few games"
Gas shotguns are pretty fun but functionally they don't do anything that a 40 quid springer wouldn't, other than I guess be easier to cock and some have a 6 shot option which I always thought did nothing other than waste ammo when I had a breacher. In terms of playstyle I find shotguns benefit most from popping in an out of cover between shots as the fire rate and magazine capacity are limiting factors.
There's a chap who is a regular at Combat South that does an upgrade service which is meant to give these guns really good range and that's where my mates currently is. As we should be heading to Rift COM 3 next weekend I am hoping to see what the effective range is like as they have a measured shooting range.