Well, for starters, Apple doesn't even make MacBooks anymore, so you can't get one. You'd be getting either a MacBook Air or a MacBook Pro, depending on your interests.
If you're talking about
this model, I had the same unit in black before I upgraded to a mid-2012.
I should think it would go without saying that the machine is hugely more responsive, due to a much faster processor, much faster and more powerful video card, and the capability of installing more RAM. Yes, on Internet surfing and everything else, particularly anything graphic-intensive like iPhoto, Photoshop etc.
In addition, I can take advantage of many of Yosemite's/iOS 8's lead features using this machine that the mid-2009 could not, such as Handoff and Continuity. This has turned out to be a HUGE time-saver for me. Having Bluetooth 4.0 means I can buy a recent-model fitness tracker that won't work with older equipment. Having a Thunderbolt port and a USB 3 port means that through either connection I can perform backups just ridiculously much faster than using USB 2. Backlit keys are nice, the much higher-quality LED screen is great, trackpad gestures are pretty cool, knowing I won't be cut out of the next OS update, being confident that I can buy an iPhone 6s or iPhone 7 in a year or two and it will work with my current machine, being able to play reasonably high end games or watch 1080p movies without stuttering or dropped frames ... opening iPhoto without having to go make a cup of tea while I wait for the library to load ... really I could go on ...