Hi George,
Phoenix Sim has 2 pattern planes in it.  It has the Integral and the Alliance.  They fly pretty well.  Real Flight has the ability to add-on aircraft and there are some models out there of vairous pattern ships.  Real Flight already has an SDK but Phoenix does not therefore, the only add-ons for Phoenix will be from Phoenix at least for a little while.

I just went through the process of deciding on a sim and I picked Phoenix.  Phoenix updates are free for life.  Real Flight, you have to purchase any updates.  I've flown the Real Flight at the hobby shop and people also say that the graphics are better in Real Flight but for practice, Phoenix does fine.  I do, however, have a high powered PC so I can run things crazy fast with either sim.  Additionally, we "occasionally" have online pattern contests that are announced here in the forums.  We have been using the Phoenix sim for this which is another reason I chose Phoenix over Real Flight.  Real Flight does have an online feature but I don't know anything about it.  Generally, people say Real Flight is better for planes and Phoenix is better for helis.  I think everyone has an opinion and the Integral and Alliance do fine for practice and you'll be happy with either choice

Scott