Linear vs OOP and vice versa

Hi everybody, I'm sorta the head programmer of my company (working there the longest, with about 5 programmers, some junior, majority senior). End of 2002 we started a test project where I dove into OOP. I had the biggest fun finding out how it works and how different you need to think to use the fullest extent of its possibilities.... Now were are about to create a new project and I want to have the majority of the code in OOP. Others are a bit reluctant because they have heard that OOP is difficult and that it doesnt really offer much advantages over linear programming. I disagreed and told everybody that it does have advantages, like the blackbox theory, the library part etc etc. They keep bitchin' that its slower on the server when you includes a bunch of classes and that it has much overhead in that matter. What are the main disadvantages of linear vs OOP? Hope someone can antweser these questions! Thnx! -Ronald H the Netherlands