There will always be a (percieved) delay in upshift as it is just a standard auto box with torque converter and not twin clutch style, but its not more than changing gear yourself, its only about half a second for it to do the full change, let alone react to you. You soon get used ot the sensation, and actually it does it quicker than most humans can, bar race, test or exceptionally good drivers. Put it this way, from the lights, I can keep up with my mate in his Evo running ~380HP, if not beat him on a good day. They are about the same weight and I think my car looses out by about 30HP, but he has 4WD to launch him.
There are a few funnies with it though. It also doesnt like to be driven in manual unless you are giving it some. At half assed city driving speeds, the manual mode really does feel like it does slow shifts. Try them flat out and they are perfect. If not driving flat out you are far better off in full auto, but use the padddles to shift still and that will overrride it. Also when city driving, if you change and dont accelerate, the torque converter wont lock, which gives you a very detached feeling as when you then do get on the accelerator, it takes half a second or so (depending on how hard you accelerate) to lock the torque converter which can feel like a slipping clutch.