Well for the last 6 years I have driven Hondas and moved from a JDM Integra DC2 to the Z, so I had to think about everything you have just asked! Would it still be fun?!
The Intergra is one of those cars you just have to own, its fantastic and as with the Ep3 they are so easy to drive, you just chuck them into corners and come out of them whailing in VTEC!
Overall I do miss the DC2 some of the time, but 90% of the time the Z just ticks all the boxes. As said above its a TOTALLY different way of driving and they do feel really heavy in comparison but the sound of the V6 is unbelievable (better than VTEC IMO). You have to drive the Z with care, but you will definately feel the power difference in 3rd onwards and can get to very illegal speeds without realising.
The guy that said their Z got more looks than the EP3, totally agree!! I have gotten a load more admiring looks and comments about my Z than I ever got about my Integra, and my Integra was such a clean car.
Take a few test drives in a Z, you will see what we mean. But just dont get hung up on comparing them as they are two different ends of the car spectrum. Z is a cruiser and not something you throw into corners hard (unless you have an awesome suspension set up as said above!).