If you're processing RAW files (especially big ones), you're definitely going to need 8 GB of RAM.
The Haswell i5 and i7 are great processors. i7 on Surface Pro 3 is getting a bad rap. Let's be clear, the i5 is still the sweet spot for the Surface Pro 3 because of the heat throttling and because of pricing. However, i7 is still faster under most workflows including editing RAW pictures or doing Photoshop, InDesign, etc. Where throttling becomes a problem with i7 on SP3 is under sustained heavy loads like with gaming or with video rendering (note: rendering, not editing. when you edit, you are using bursts of CPU speed, not sustained speed). And let's be clear, the throttling doesn't mean your SP3 i7 is slower than an SP3 i5. It means that the extra money you spent for i7 speed is wasted when you are doing sustained load.
The Surface Pro 4 is fantastic but most of the improvements are in the 10-15% range over the SP3 and more a refinement than anything else. The refinements are fantastic and may be enough to get you to pay for it. Like the new screen is gorgeous. And Windows Hello works so well. I love my Surface Pro 4 (i7/8GB/256GB). If you have the budget and feel comfortable spending it, then do so.
It's getting harder and harder for manufacturers to justify people upgrade their PCs on such a rapid pace. The Haswell Core series processors are still fantastic and will be good for quite a number of years. Things in the industry change at an evolutionary rate. You can either wait for the new sexy 2016 Prius and pay for the latest thing or buy a new 2015 Prius (which is still a great car) and save some money. But it's getting harder and harder to get a bad machine these days (as long as you're not buying a budget PC). A lot of terrific options out there for all needs. We're more arguing niggling points like should I get the nav system or not? Should I get the sunroof or not? Because no matter what machine you get, the performance is going to be good (though that 8 GB is necessary).
However, I hate to say this, but my main machine is still my Surface Pro 2 with Windows 8.1 (i5/8GB/512GB). It's the exact same Haswell i5 as the SP3 i5. The only reason I say this is because 8.1 is more stable than 10 at this point in time because 8.1 has been around for awhile whereas everyone is scrambling to update Windows 10 (Microsoft with the OS, vendors with their hardware devices like Intel). Not that I don't use my Surface Pro 4. I use it a great deal but when I need to work on a project for work, I grab my SP2 first. I never worry about picking up my SP2 and not having a lot of battery left. Plus, my SP2 has a battery cover which almost doubles my mobile battery life. The SP4 has no battery type cover option.
Another reason is I use the pen a lot in Photoshop and Illustrator and the Wacom technology is better than N-Trig. It's a shame that Microsoft couldn't acquire Wacom. But getting N-Trig was easier to do.
And there's one aspect of the SP2 that is kind of blasphemous in public opinion. Although the SP2 is thick as a brick and weighs more than the SP3/SP4, I find it actually less awkward to manipulate in certain situations like standing up or when in bed because of the smaller dimensions. The kickstand is easier to manipulate, having only 2 positions. The stiffness of the SP4 kickstand is great and it allows almost an infinite amount of positions, but in certain situations, it makes it difficult to adjust. The SP2 kickstand is just pop, pop.
I thought hard about getting the SP3 when it first came out but after realizing it essentially had the same guts as the SP2 and how happy I was with the SP2, I stepped away from the ledge. I played with it so much at the store and it wasn't worth spending $1500 to upgrade. The SP4 was just enough to get me to upgrade especially for the Iris graphics that comes with the i7 and that gorgeous screen (as well as the upgraded cameras and Windows Hello).
Facebook
Twitter
Instagram