First, I am not sure the problem is the Laptop, or the OS. I have a 15" Retina Macbook Pro (2013) that has been getting slower and slower when accessing websites, whatever the browser (I usually use Chrome and Safari). I am using Wifi. This is getting annoying, to the point where I sometimes need to either restart the Wifi or the laptop itself. I think it appeared gradually but I am 99% sure it was not there before the upgrade to Mavericks. I made comparisons with other laptops (I also have an old 15" MBP I am using to type this message, and an iPad Air; both work much much better). Is there any known issue I should look for ? Thanks.