The Bandit 1250S spoiled me with it's comfort (compared to my '06 Gixxer Thou') and real world performance. A few mods made a big difference in comfort. I flipped the stock footpegs 180 degrees. This moves the pegs about 1-1/2" down and 1" forward. I also raised the front of the seat only to keep the boys from slamming the tank under hard braking. A MRA Touring windshield from Twistedthrottle.com brought the wind factor under control. The wind now hits my helmet at the top of my chinbar instead of lower chest. No buffeting or pushing you forward from negative pressure, just good clean air. No extra wind noise either.
Lastly, I dropped the front sprocket one tooth to a 17 tooth unit. It made a noticeable change in first and second gear acceleration and has allowed me to carry one gear higher while maintaining a decent pull out of the corners. It certainly isn't a life-changing mod, but it has some benefit. The front wheel still stays planted and the speedo is even furhter off. Can't comment on gas mileage or how it has affected top speed yet.
The only mod I'm considering next is a switch to Dunlopad HH+ front brake pads. The stockers work fine but require more pull to get equal braking to my GSXR. Initially, the Gixxer had the same problem and the DP pads transformed that bike for considerably less than stainless brake lines. I MAY do that, there is a bit of an advantage to the less immediate pull of the stock pads under normal conditions and they will stop you quickly when needed. It just requires a fair amount of pressure. Engine mods are a "maybe" and a bit away, at best. I like the quiet stock pipe. If Dale's ECU and K&N filter can make a worthwhile difference with the stock pipe, I may go that route. If not, I'll have to get bored before buying a louder pipe. Cheers, Jack