+100, Bought mine bone stock 2400 miles. Stage 1 was noticeable.
Stage 2 feels like I added 100cc's and made me glad I upgraded the suspension.
http://new.holeshot.com/images/suzuki/bandit/650-1250/dynocharts/1250_dynochart02.jpg
Some Motorcycles don't benefit much from intake and exhaust mods, proven by many magazine articles and confirmed by Dyno runs.
The Bandit 1200 & 1250 both benefit greatly from said mods.
Dale Walker has taken both these models to the pinnacle of their capabilities.
I have followed his advice and used his products over the years Dand never have been disappointed.
Did you notice that 100cc boost just above 5-6K or all throughout, bottom end too?