The biggest advantage I find with gesture based typing is for one-handed use. I normally touch type in landscape when I can use the device with two hands. On occasion, it is not convenient or not possible for me to use a device two-handed or in landscape orientation. In these situations, gesture typing in portrait is what I do. For gesture typing, I find that Swype is the best, Google keyboard is a close second and Kii to be third best. SwiftKey Flow is a distant 4th.
Yeah, at Couch's recommendation, I'm giving Swype a try. The gesture based typing on Swype is pretty great, best I've used so far. Touchkey typing, ehh...not so great. I'll keep at it for a while longer to give it a chance though.