Replying is probably a mute point now given your purchase but I'll throw my views into the mix. I have a few of the add-ons mentioned and in my view they all have pros and cons.
Aerosoft Airbus X (Installed) - I think this has the best external model and VC of the Airbus add-ons I have. It comes with the A320 and A321 and includes both engine types. Systems wise its a step up from default and I like the way the FMC is functional and integrated into the AP. The sounds are excellent. I have never had any of the problems mentioned here regarding flight stability and tend to fly this Airbus the most and really enjoy it.
BlackBox A320 (Installed) - This has a simpler external model than the Airbus X with a much lower polygon count, but what you loose in eye candy I have found you make up for tremendously in performance, so it's an ideal candidate for lower spec'd machines. You get the A318, A319 and A320 models with both engine types. The VC is very good and benefits visually from a high polygon count, it also has lots of 2D panels. The sound set is very good. From a systems point of view it beats Airbus X hands down as Blackbox have programmed their own FBW system. While its a prolouge it's evolving into a very thourough simulation of the Airbus A320 family. It does have some technical issues at the moment on systems running 64 bit Windows 7, you have to start FSX in Admin mode or the PFD's wont display information, this is annoying if you are using an external FPS limiter.
Just Flight A320 (Not currently installed) - A step up from the default A321. Visually it comes with both engine types and to my eye the external model is in between the default and Blackbox A320's so is another good performer on lower spec'd machines. The VC is a step up from the default A321. Systems are pretty much similar to the default with some additional functionality and an FMC, though this is limited. The sounds are good. Its probably an ideal add-on for beginners. You can buy the A318, 319 and 321 as separate standalone variants.
The FSlabs add-on looks very promising and may well replace all the others I have in my hangar if it delivers the goods.
Ian, I too had A320 Airbus on the old Amiga computer -->
http://www.myabandonware.com/game/a320-air...tion-europa-1bq