I own 10 8 7 evo sls and have previous model 8 7 6 5
I’ve flown the 8m in under powered to had to come in and get my 6m. I have not flown back to back with previous models but I have a lot of time on them.
The 8m in particular is a quicker turning kite and the kites fly more out in front, easier to get up wind, there is definitely more boost and hang time.
I’m not sure I really notice the weight difference when flying but the sls climbs better. Weight is definitely noticeable when you pick up the kite.