My sl is a lot softer than my normal supera.I had a 14lb carp on sl a few weeks back .it did bend a lot but did the job.
But if using for larger carp with intension i would use my normal supera .they are much stiffer .infact i bought it off a guy who bought for bream fishing but wanted a softer rod
I have a 10ft Supera feeder rod 2oz 1.5 oz and 1oz tips brilliant rod ,bought it ten months ago, caught carp of all sizes up to double figures, the rod is always up-to the job never felt under gunned , even with the odd ballistic animal,
At the moment the same rod is being used to catch skimmers, and F1 from 8oz to 2lbs with no problems.
The Supera SL would be softer but given the choice I would choose the standard Supera, specially in the 10ft you will not be disappointed, that's if you can find one for sale, they are like gold at the moment stocks are low in all the tackle shops, and on line, good angling