First of all I am 5ft 10-11" and have a 34"inseam 140lbs (10stone). Tested On the Tryweryn COMFORT: Compared to the S6 the Air 45 is really comfy and i could get the seat 2 notches forward with the bulkhead in and 3 without. i really liked the backrest and the thighbraces as you could get very tight in the boat whilst still been really comfy. Another advantage is that by having the metal seat rails you can easily attach a lap-belt to the boat. FLATWATER: The Air 45 was a little harder than the S6 to get the ends down but was very stable on either end. gr8 fun. It was very easy to stall and had a lot of bounce which makes learning Flatwater loops easy. HOLE: loops were great although not aerial but thats mainly due to the type of stopper i was in (top hole) and my ability although it had loads more pop than my S6 did. It splitwheels very well which is good and when cartwheeling it is very and balanced...