By having a very short intake runner/plenum ie. at the TGV's it makes the drivability and idle a little more erratic. The intake pulses will be very noticeable and may cause a few challenges for your tuner, only at low rpm were the throttle blade is partially open. The air velocity will not be constant and scavenging of the cylinders will be compromised. At idle boost is pretty neglible and the engine will rely on its abililty to scavenge the cylinders to run 'smooth'
Just out of curiosity my TAFE lecturer designed an intake manifold that was about 20ft in total. The idle on it was so smooth and the drivability was very good. Totally impractical but he was a bit weird... Just wanted to prove that the longer the runner after the throttle blade the smoother the engine actually ran...
My 2c...