I've seen a few reviews of these - with seemingly good reports...

Anyone heard of them, handled them?

I have had a 410E for a few years now. Very happy with it,accurate,powerful and very quite. My favorite hunting rig. Can not go wrong with an Air Arms rifle.

pretty much sums it up

The Specialist recommended AA when I was shopping around for a sub £500 gun, and I have been very grateful for his advice. I was quite keen on getting something like a BSA scorpion, being compact and within budget (but what swayed the vote was that BSA do not offer a left-handed stock version, although you can reverse the bolt with this rifle). I settled with a AA S410 carbine (it was a little over budget, but don't regret it one bit) and so far have been pleasantly surprised. BSA do offer some of their top end models like the super10 with left-handed stocks, but the super10 was a little out of my price range, although I have heard very good reports about it.

If you do not have any restrictions on callibre or power, I would recommend the S410 FAC extra. It is really long, but well balanced and gives you a top end power of over 30ft/lbs in .22 and you can adjust it right down to about 10ft/lbs for indoor ratting/plinking. To top it all off though, all their rifles seem to be very accurate out of the box with diabollo-pellets, which at the end of the day is most important and if you have power too you may be able to have your cake and eat it.