Had my 2007 macbook for about 6 years now. Shits still doesnt lag. but apple is coming to a down fall, so i suggest you get one of those ultrabooks now, because apple is becoming a asshole. sueing left and right, monopolizing connectors(lighting, thunderbolt), and uninnovative technology. Apple had its reign and its just about over.
The people behind the company may seem like douchebags, but the products are still very great in terms of quality and style. I love my MacBook Pro. It's going to be my fourth year using this laptop, and I don't have problems with it. I might need to replace the battery, though, but I'm considering getting a new MacBook Pro for college. The new and thinner one with the Retina display seems great.