Looking at buying one as an inexpensive way to use OS X (I think it can run El Capitan). My only requirement is that it can play 1080p YouTube videos flawlessly (no stutter).
I don't have a 2009 MacBook but I started up my maxed out early 2008 MacBook 4,1 (2.4 GHz, 4GB RAM) and it stutters with 720P in Safari and Chrome and is demolished by 1080P in Chrome. One bug difference between the 4,1 and the 5,2 is that the 5,2 has an actual graphics card. There might be hope yet!
I don't have a 2009 MacBook but I started up my maxed out early 2008 MacBook 4,1 (2.4 GHz, 4GB RAM) and it stutters with 720P in Safari and Chrome and is demolished by 1080P in Chrome. One bug difference between the 4,1 and the 5,2 is that the 5,2 has an actual graphics card. There might be hope yet!