However, it packs some serious internal upgrades that make a difference in day - to - day use. (cultofmac.com)
There are several big internal upgrades as well, including a heart rate monitor and GPS. (slashgear.com)
But when it comes to determining what type of return - on - investment you'll get with internal upgrades, such as soundproofing or extra insulation, I have to say it's negligible, at best. (moneysense.ca)