There may be other benefits to using a more expensive fuel other than mpg/power gains, for example better additives to maintain your mpg.
Regarding port cleaning I'm not sure this is a big issue. Carbon build-up on inlet valves can be an issue for direct injection engines but no fuel additive can correct that as the fuel doesn't touch the inlet valves, which is the reason for the problem in the first place. This certainly isn't an issue for the CT200h as it isn't a direct injection engine.
CT200h, RX450h, NX300h aren't direct injection, the IS300h, GS300h, and GS450h are.