I noticed something today and dont know if there is a problem or if its just the way the throttle by wire thing works. Sitting still, either park or neutral, when i give it some gas and rev from idle (1500ish rpm) to say 3000 rpm and let off the pedal it hangs for sec then sloooowly decreases back down to idle. Normal? Why the lag?

Throttle by wire is possibly what you feel. Feels like someone else is helping with the throttle from what I understand. But I think you may be talking about the 3000rpm neutral rev limiter.

Its not the rev limiter, that is a different feel. Most cars i have ever had when you rev the engine its pretty instant that the rpm's drop when you let go of the gas, this almost feels like its stuck or something, rpm's drop very very slowly after letting off the pedal. I would say almost a full 2-3 seconds it hangs at 2800-3000 rpm before it starts to get back down to idle.

Compared to a carb car I'd say most fuel injected computer controlled cars are kinda like that, some more than others. Its probably the TBW.

Maybe your AC was on? But probably the it's the drive by wire thing.

no it's the throttle by wire. It's not that it's not fast enough...for whatever reason they set it up that way. maybe to make it smoother when revving or who knows. But in neutral it;'s real slow going up and real slow coming down.

All LS' do this. It's got something to do with the effects of immediately stopping airflow to the engine. Whilst in the Navy the "hole snipes" were lighting off a boiler, the air/fuel mixture being manually controlled (at least then, 1978). Less air was called for and the guy shut the air off completely. Fortunately for those in the engine room, the fireball went up the stack, almost blowing the stack off the ship.

All LS' do this. It's got something to do with the effects of immediately stopping airflow to the engine. Whilst in the Navy the "hole snipes" were lighting off a boiler, the air/fuel mixture being manually controlled (at least then, 1978). Less air was called for and the guy shut the air off completely. Fortunately for those in the engine room, the fireball went up the stack, almost blowing the stack off the ship.
Wow...just showed off your age :) Good times.

yea it did - but good story thogh.