T7600 for the 520, and I got a T7800 on the way for the 530.
So far I am happy as Odamex does work well as does EasyRPG, both of which I'm still developing for.
Other than that, I've only tested Odyssey, Dark Places, and ZSNES. ZSNES aside, performance was very acceptable. I've still to set up ScummVM (assuming it's up to date), and UAE, but ya, I don't regret buying these lap tops at all. It's about what you would expect from supported hardware that lacks a graphics card with the dedicated memory required to run Jedi Outcast and the like correctly.