I recently purchased the A2A B-377 Stratocruiser just for kicks and it has proven to be the best addon I have ever laid my hands on.
The level of realism is just awesome. It's very much a systems aircraft where every knob, switch and lever is operational. It even fogs the cockpit windows when gaining altitude and requires to turn on the defrost to clear it up again.
Take a look at this picture. It's the end result of my first attempt to take-off with this brute:
http://i844.photobucket.com/albums/ab1/RacingLad/2009-10-4_22-38-59-468.jpgAfter reading the manual I realized what went wrong. I forgot (out of ignorance) to engage the ADI system (water injection) before applying full power and thus all four engines went kaputt. It's a good thing I still had 3/4 of runway left when the engines caught fire.
Seriously, this the first time I popped an engine because I didn't follow the proper procedures. This is the level of realism that this addon provides. I recommend it to everyone and the level of detail is also awesome.
Buy it!! It's cheap...
Cheerz!