Hit and Miss...
They seem to be very hit and miss if you'll excuse the pun. I've had several over the years as I like the light weight and pointability. It's also easy to cock.
I currently have a .25 which I'm very pleased with. Very pellet-fussy (I've tried everything I can get my hands on until finally settling on FTTs).
It's a little cracker and will shoot consistently fine at 30 yards. The build quality is very good and the lock up extremely positive. It's really quite smooth so also doesn't shake the scope to pieces. Personally I only shoot air rifles to practice for Sporting Rifle in my garden when I can't get to the range so I like a gun with a bit of a recoil as it's more like the real thing - I don't like PCPs for this reason as they give you no feedback. I also like the larger pellets as have always found .177 a bit fiddly - It's just as challenging to shoot offhand at 20 - 30 yards as supported at 45 yards and surely, half the fun of shooting is getting a bit of a kick rather than a deafening phut...
I think I've been lucky with mine from what I read as people do seem to have problems but I find the XL fun to own and challenging to shoot well.
El-bow, the Spanish Archer