Don't be afraid to buy the older model, if it suits your needs better.
Apple regularly refreshes its products, but sometimes newer isn't better. It's important to figure out how you're going to use a MacBook Pro—or any Mac—before you can be sure you're getting the best bang for the buck.
I could either get the base version of the 15" 2015 macbook pro, or the higher end 15" 2014 model. I want to use this machine for at least 4 years. I use photography software and am a maths+computer science major...Do you think the new Force touch trackpad is worth it, compared to the added computing power I'd get from the 2014 model? — S.M.
Apple updated the 15-inch Retina MacBook Pro this past May. It upgraded the high-end 15-inch MacBook Pro's graphics processor and also added the "Force Touch" trackpad that we've been seeing more and more since the MacBook rolled out in April. But it really hasn't done much else with the device.
Apple was in a bit of a quandary. The 15-inch MacBook Pro demands a higher-power, higher-performance CPU. Intel has been much later than it originally expected to deliver fifth-generation Core i5 and i7 processors based on its "Broadwell" chip design, so Apple put in the same Haswell chips as were in last year's model.
That's not to say the 2015 version of the 15-inch rMBP went entirely untouched except for the Force Touch trackpad. As I said, the premium model got a faster graphics processor. All 15-inch models also got faster flash storage and some improved efficiencies that result in an additional hour of expected battery life.
As far as the Force Touch trackpad is concerned, I think it's really cool. I'm sure developers will make use of the API as time goes on, but remember that the vast majority of Mac users have Macs that don't support Force Touch-specific features, so I think we're a way off from seeing it as a "killer app" feature that you absolutely have to have.
Still, given your needs specifically — photo processing and computationally intensive work — you're probably better off going with the higher-end 2014 model, which is going to give you a very solid bang for the buck.
Really, though, you can't go wrong with either 15-inch Retina MacBook Pro model. I'm using an early 2013 model which I've had since it was new, and it's still the best Mac I've ever laid my hands on. I love mine to death — I'm sure you will too!