Here's a gem I just found a day or two ago - a freeware Mirage III that looks as good as the Skysim one. It's available at the Mirage4fs.com website, and was released by Beat Schaffner and Warrick Carter. http://www.mirage4fs.com/mirage3_all.html
It's not just a sharp exterior model either - it comes with an accurate 2D panel, and an even better VC:
An excellent find! Truly amazing that theses guys put so much time and effort into a such a quality project and then distribute it as freeware...awesome.
Remember the 50-50-90 rule. Anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong!
IMHO, there are only a couple improvements I would suggest on this one: - More varied loadouts/external models and paint schemes - It's very frame-rate heavy when using the 2D panel. VC, Tower, and Chase views give good framerates (18-25fps, and I'm locked at 25fps), but the 2D panel mode drops it down to 8-10fps.
Those are the only things I have found that could use improvement.