Hyundai Repair: Adjusting throttle response, programming issue, factory warranty

Question
My 2006 3.3 V6 Sonata GLS has a distinctive lag in throttle response at 30-40mph.  If just doesn't accelerate smoothly.  Hesitates.   I've got 23K miles.  Time for tune-up?   Is there a chip modification to consider?

Answer
The only TSB I see that may be related is a reprogramming to reduce a 5 --> 2 shift delay at approximately 40 - 50 MPH.  

You won't need a tune up until 60K.  

At this point, it'd be my speculation that if this is a relatively new occurrence, there's something wrong that should be repairable under the factory warranty.  If the car is doing the same thing it's been doing since new, then it's possible it's normal or that it's a programming issue for which Hyundai hasn't released an update.