I would say Y510P will be a better pick,just picked one up for my mom and she has no complains for it,but the glossy screen requires a little more focus if you bring it outdoors that is due to the glare interfering one's view.Otherwise the laptop is good the build quality is almost top notch with aluminums in and out and some hard plastic as well.Besides that,like most mentioned,the ultra bay is actually quite useful in the future can be replaced with various type of accessories.With the price tag being lower than the Msi,you can always use the balance for an SSD upgrade.Then it's pretty much a pocket rocket device you have.

The screen is as bad as you think.I have personally tested both Y5xx series (y500&510) and the screen looks perfect in indoors.Well it also work perfectly outdoors provided the fact that u have no strong lights and sunlights shining directly to your screen.Personally I don't mind taking another 510p for it's better design,well you have red led illuminated keyboard which is handy when you game in a dark environment? Not sure and on the other hand the msi has a thin profile which is another advantage in terms of design.However,as many ppl said the airflow inside might be a worrying factor.Still it boils down to ones preferences in terms of design and practicality so I can't force you to pick on one that you might not favor.Have you seen both models in person? Since you really an anti glare screen then look ahead on the msi.