Piss-Off Plant Questions

I am going to be placing an order in the near future and have a few questions regarding your plants.
Piss-Off Plant: annual or perennial? What is the size of the plant at maturity? Are they hard to grow?

The Piss-Off Plant (Plectranthus sp.) is a tender perennial. Its hardiness rating is unknown but we believe it is 11+ which means that the plant will winter outdoors only in semi-tropical and tropical areas. In temperate zones it must be grown as a summer annual (dying when the frosts arrive in fall) or it must be brought indoors. It makes a good pot plant or basket plant for indoors if it gets good light.
It reaches about two feet in height, possibly higher in warmer zones. It is *very* easy to grow. It tolerates abuse very well, such as occasional missed waterings.