I play the Wings over Europe version as it is the latest. There are after market terrain add ons. Both pay ware and free ware. I have a pay ware Vietnam terrain and it was well worth the 15$s.
As for the aircraft, there are a few different sites that have add on aircraft. Again there are payware add ons and freeware. I have found most of the freeware aircraft are high quality and they look really good. Almost all have good looking pits, with working radar, moving maps and all that jazz.
The game is some what like AH. It has just enough realism to make it fun without needing a manual the size of a phone book to fly the aircraft right. With every thing set to hard you will find yourself flying long missions, that start out kind of boring and then it gets really busy. You find yourself setting up your weapon systems, targeting the bad guys, dodging SAMs and trying not to get nailed by the AA hiding under a tree somewhere.
The AI can be tough. Again you can scale the dificulty here too. Set it to hard and you will find yourself sweating it out in a long 10 min dogfight for your life. With the AI set to hard they give you no breaks. They are deadly. So the challenge is there.
Online play is available. I would suggest joining a squadron. I fly with VFA-25. We are now learning to fly the F/A-18As. We were flying the A-7Es. We are mostly an attack squadron. We do a lot of co-op missions together pushing mud. It is a lot of fun.
You can download the game for 30$s US. It is worth the money. It runs on low end systems, it looks pretty good and there are tons of add-on aircraft and terrains for download. You should check it out.
-Spot
