"as good as" and "as realistic as" are VERY subjective terms. What makes it not as good? Are you getting slow frame rates causing it to be jittery? Are the photofields blurry? Are you running G3 on the same computer you used to run G2? G3 is a resource hog, so a computer that ran G2 may not be sufficient to run G3...

It's a bit too late for hindsight, but there's a G3.5 demo you can download to see how good or bad (in your own opinion) it will be on your computer.

I would start with some specifics about what the problems you're having look like. Then post some specs about the machine you're running it on. Someone can probably help a bit from there.

-Case