world's heaviest flywheel?

Just took delivery of a 05 wrangler x, manual transmission. After
driving it about 50 miles, I noticed what felt like a stuck throttle
when letting off the accelerator in 2nd or 3rd at 3400 rpm or so. I
checked under the hood and the problem is not with the throttle return
- it returns promptly. But the engine continues at high rpm for a
second or two before slowing. My guess is a poor choice of engine
management logic in the factory chip - or the world's heaviest
flywheel.

I took the car in to a dealer on Saturday. No tech on duty, but a
salesman drove the car and told me it was normal behavior. I sure hope
he is wrong. I strongly dislike the sluggish response - when I let off
the gas, I want instant slowing.

Is this slushmobile performance normal for a 05 wrangler?