I don't think I would get too concerned with what brand of flight simulator you are going to get.
Any of the sims that were mentioned here would serve your purpose's well.
If you have been inactive for 15 years it will take some time to get good enough to tell the differences between sims. If you buy any of them and use them, it will help your flying considerably.
All of the sims can be adjusted to make the plane fly the way you want it to. Most people don't go to the effort to dial out unwanted characteristics, but they would be the first ones to lodge a complaint against a sim because they don't think the sim is reacting properly to their inputs, when a small adjustment to the paramiters would make the change they want.
After reading most of the sim posts, you can see where several people will think brand A is best for helicopters, and other people will think brand B & C are the best helicopter sims. The same goes for planes, graphics, and every aspect of the sims. Almost all of the sims will help you out greatly. Just don't get too wrapped up in in feed back that says one of the sims is the best, and all others are no good. Hogwash.

Greg