A lot of people have this notchy 2-3 shift. A thread was started about this. I have this notchiness, but it goes away, or at least is less evident, once the tranny warms up.

As far as breaking in the engine correctly, there was a thread a while back where people that didn't break the car in correctly weren't getting as much power out of it than people that did. Someone dod some dyno runs, and there were some drastic differences in power. The sample size was probably too small to draw any reasonable conclusions, but it did show that in one case, breaking in the engine properly can result in more power later on.

 

Dyno the car before buying and get it boroscope checked for Cylinder #4. Even if it may be covered under warranty, any repairs are just a hassle.