To be honest, and I'm using single target boss fights for an example, I've never had a problem with swiftcast Thunder III, Fire III, Raging Strikes, Fire I x5, Blizzard III, Thunder I/II (depending on MP) rinse and repeat. Thunder stays up so Thunder proc always has a chance of coming along and with Fire I x5 there is a higher chance of getting the Firestarter proc. Granted, I know people like to weave Flare into a single target rotation, and of course it does do quite the amount of damage but depending on a the tic when you Tranpose you lose time. Then you are also using more time to cast another Blizzard I or III or whatever the preference is. OR using a Convert which, in many boss battles these days, could be saved for a small adds phase.

Not saying that's wrong, but in my experience I feel like I deal damage a lot more quickly when I don't weave Flares.

/shrug