the power delivery of both cars are totally different, the stock turbos and exhaust system is a joke ( if you have ever seend the dump pipe and manifold setup you will seriously laugh it has the good old T style dump pipe so the two turbos are constantly fighting against each other)...
the torque of the 1jz is huge like the car pulls from very down low but anything after 6,700rpm sounds like it is really struggling, (although i am only running a cat-back exhaust). But as soon as you bolt on that big single then you are cooking with gas.
as for chassis, i think toyota spent their money on developing the motor more than developing a sleek sporty chassis. I prefer the look of the r33 and it is definatly more nible than the soarer. But when it comes down to it if you time money and effort to do a conversion into a different chassis or do something like shane then you will never look back...
if only toyota released a similar chassis to the s13 with a 1jz just like me hehe