hi,
the manta 69 was more freeride kind of board for me. i compared with the iSonic 111. manta was nice easy jibe and confortable but slower. if you have the opportunity to try it that would be the best feedback for you. if you check the korean pwa result right now, after the first race 7 iSonic in the top 10. maybe you never hear about the first turkish guy, who beat antoine - on iSonic. maybe this is more credible than my experience...
gyurmo