Pretty solid advice here and I agree with what Ken and Bill are saying.

I happen to be an AFPD guy and personally would not be satisfied with anything less. I like the ease of modification to the models I get with AFPD that alow me to play with the physical characteristics to get the sim planes to handle all but exactly like the real thing. This is CRITICAL to getting the most out of a sim. One thing you will run into is planes that are either way less stable or way more stable than the real thing. Being able to modify CG, thrust, prop size, pitch, engine performance, incidence in the wing and stab, manipulate dihedral, area and weights of various componants is an incredible tool to allow you to achieve realistic performance. Dont get me wrong, the stock AFPD planes are very realistic, most of the ones that are a little "off" are the downloads. The 3D planes tend to be helium filled and the scale planes fly too heavy.

With AFPD I practice pattern and IMAC using the downloadable scenery that contains a grid in the sky and I also LOVE it for 3D. I can honestly say that after I received AFPD on 12/17/04 my skills began to exponentially improve. Within a couple of months I was able to not only perform but very cleanly perform maneuvers that would have taken years to learn otherwise.