I only grow one single-crown chimera: Emerald City. It seems pretty hardy to me and a constant bloomer. Mine has been blooming nonstop since last summer. It survived a rather cold winter in my drafty room here in NY.
Chimeras don't really have any special requirements. You take care of it, just like you would any other AV.

I have three chimeras. Ness' cranberry Swirl (standard), Pixie runaround Sport (mini trailer) and sunray trail (standard trailer). none of them are getting different attention from the other plants. and they all are growing well for me (i only just got sunray trail, but it's putting on new crowns and blooms in a hurry already :-) )

Thank you both, that's very helpful! Jonboy, I'm also from NY. The AV's are by my kitchen window sill which gets very drafty in the winter. I guess the plants should be moved because of the cold draft?