Help ID this hardy hibiscus

I have this compact (under 4') hardy hibiscus that is just great, but
I lost the tag during the first winter.
It grows in half-shade with little irrigation, blooms profusely with huge
at least 8" flowers and does not need staking. The bush is rather
compact at 3'x3'.

I posted the picture at the Identification forum
http://davesgarden.com/forums/fp.php?pid=2869084
and was pretty sure that I ID'd it correctly until I started looking really
closely at the plant files.

I cannot really tell the difference between Rainier Red, Disco Bell Red and
Luna Red. I am inclined to cross out Rainier Red as it does not seem
to be as compact.

Any help will be appreciated.