I think that the AA s410 wins hands down, although it has less shots per fill.
much easier on the eyes :unsure: better build quality, better after sales service, better trigger, loads of accessories available. you get the idea.
the S16 is very heavy and has a very long pull length, not really ideal for lugging aroud the fields all day, but its just about bomb proof and more or less an all weather gun.
If you do get a good S16 then your lucks in, but if not then a little work might be needed
if it was my choice id go for the AA s410. but at the end of the day its 'horses for courses' really.
also depending on what method of charging you use pump or bottle the AA is charged to about 180-190bar, (much easier using a bottle, if you have to use a pump its not to hard ) giving about 70shots .177 and 80-90 in .22 depending on your set up. all the AA i've had liked a diet of either AA own pellet, Daystate's or Lazadomes in 4.52 and 5.51
HTH nickc