No, I would not say it is worth the visit. The only way I would rocommend this park is if you really want 6 more credits.
I think Six Flags would be better off selling SFKK (and SFA), and giving some of their rides to other Six Flags parks.
When I visited SFKK for the first time a couple weeks ago, it was horrible. Every coaster except Roadrunner ran one train, and when the trains on the coasters finally would come in the station, the ride operators would just be talking to each other and were in no hurry to open gates/check restraints/send the trains out.
IMO, it's just a bad park that is ruining Six Flags' reputation.
Sfkk is not a bad park. Six flags has ruin this park rep. B4 this park was sixflags, kings island and kk was about on the same level, and ever since sf came, da park hast got a desent new fresh coaster not use from another park (greezed lightin), also sf took out many of this park rides b4 sixflags took over. also i wld like to say sf only put into this park grezzed lightin, mega wedgie,tornado and deluge since 2003, everything else was invested by this parks very first owner or ed hart.