Not really. At the velocities we're shooting, the extra length is not going to affect accuracy nearly as much as the 4" to 8" reduction is going to improve handling with a carbine or defense sub-carbine, or submachinegun. Remember that maintaining the velocity required for lethality to 500m is not important in airsoft, and close quarters maneuverability is often much more important than long range accuracy when dealing with small hard cover or thick brush.
It's all a matter of opinion, however, and in the long run, go with what you think looks the best and are most comfortable handling. There's very little difference in performance between different models of AEG. Even if there is a major difference, it can be made up for in upgrades quite easily in most cases.
As far as recommendation of what manufacturer to buy from, I LOVE my new G&G. It is one of the best performers among the AEGs I have access to and it's still stock, as well as being a good ~$100 less expensive than the others (CA high-grade B&T, TM, ICS high-grade AK, JG). Also, because I opted for the shorter weapon (7" barrel M4CQD), it's VERY loud and snappy compared to longer AEGs, especially with the large open flash hider that it comes with.
*edit: beaten to accuracy answer