Well, seeing as my car is a shitbox 32, I rate it pretty poorly
But as for a JZX100, I drove a 34 coupe and my old 100 back to back and I can say performance wise they are pretty well on par. Similar power delivery (100 has a bit more bottom-mid) and similar feel when chucking them around (which is pretty good considering the extra weight of the 100).
On stock sus, the 100 feels heaps nicer to drive, but has a bit more roll and pitch than a stock sus 34. Coilovers even it up and with sways too, mine was in GTR spec handling territory.
I thought the interior of the 34 was a bit boy racerish, where as the 100 has a nice comfy Camry-like interior which is a great place to sit when tootling to and from work. Also seats any mates who want to come for a drive a lot better than a 34.
Looks are subjective, but I don't think theres any competition there, 100 all the way
In summary, the 100 is something you can enjoy every day in comfort, and still bust hills runs and keep up with most cars. The 34 would be on par in the hills, yet a bit harsher for every day use. Not to mention the cop attention is chalk and cheese, my old 100 had straight pipes and flush fitment and I barely got a second look from cops. You chuck a set of wheels on a Skyline and every cop looks at you with dollar signs in their eyes.