there is basic difference in pro-e and catia is when you r skething any geometry in pro-e every time u have to provide referances or system will take difault ref. i.e.horizontal and vertical. and in case catia u will not required it.
anothe is in catia point tangency cnsider means u can't add material between any geometri and point.but in case pro u can add material.
What Rudresh is telling is correct.... Catia is more expensive than Pro-E.. But even Catia is useful for engine n transmission systems. My friends are also workingin that field only. They r using Catia for designing transmission systems.
Catia is mostly used for Class 1, Class 2 surface modeling in Cars, Aerospace. Even I am using Catia v5r16 for modelling Ship Hull surface. And it is working great. No other software is more useful in my case. They got seperate modules Ship design and Aerospace.
Most of the industries(who got projects in both surfacing and solid modeling)are using Catia V5 effectively.