Hi there, I am currently running a Mid-2012 model 15-inch MacBook Pro Retina with the 2.3 GHz I7-3615QM processor, 8 GB of RAM, a 256 GB SSD and a GeForce GT 650M GPU (1 GB of dedicated memory). I use it alongside a 32 GB iPad Air and a 64 GB iPhone 6, and at home I connect it to the Thunderbolt Display as I need to work with radiological images, 3D representations of anatomical structures and large tables for data entry of clinical studies, so I'm not considering to buy anything else than another Apple product... and this is also because I haven't been disappointed a single time after five purchases (gone is an iPhone 5S now being used by my mother). I have been waiting for the new model, but... no, you won't read disappointed thoughts about the 2016 MBP (though I really can understand them, because I am too not convinced by the newer models). I am trying to look at things from a technical point of view, but being ignorant about the details I decided to kindly ask for your help in discerning the pros and cons of different versions. I already decided not to replace the cooked battery of my 2012 MBP and to leave it at home as a desktop, hooked up to the Thunderbolt Display and with a wired Ethernet connection. To replace it as a mobile workhorse I am thinking of choosing between two versions of the now-discontinued Mid-2015 15-inch MacBook Pro Retina, as my usual seller is beginning to discount them. They come in fixed configuration, so I can choose between the following. I7-4870HQ (2.5 GHz) + 16 GB RAM + 512 GB SSD + AMD Radeon R9 M370X (2 GB GDDR5). I7-4980HQ (2.8 GHz) + 16 GB RAM + 512 GB SSD + AMD Radeon R9 M370X (2 GB GDDR5). I7-4980HQ (2.8 GHz) + 16 GB RAM + 1 TB SSD + AMD Radeon R9 M370X (2 GB GDDR5). Prices are, respectively, 2199 CHF (2263 USD); 2599 CHF (2674 USD); 2999 CHF (3086 USD). The first and less expensive one would normally sell for 2499 CHF (2571 USD), so I'm looking at a 12% discount. The second and third have a "SALE" badge on their product page but their price did not vary from the one I saw before the new ones came out (maybe it will drop in the immediate future). To put things in perspective, Apple offers me, between others, the following comparable configurations. I7-6700HQ (2.6 GHz) + 16 GB RAM + 512 GB SSD + AMD Radeon Pro 450 (2 GB GDDR5). I7-6820HQ (2.7 GHz) + 16 GB RAM + 512 GB SSD + AMD Radeon Pro 455 (2 GB GDDR5). I7-4770HQ (2.5 GHz) + 16 GB RAM + 512 GB SSD + Intel Iris Pro Graphics. The less expensive new model comes in at 2919 CHF (3000 USD), while for the best equipped new-generation MBP Apple asks me 3149 CHF (3236 USD), while the previous-generation offering (the last one listed), is sold at 2589 CHF (2661 USD), which puts it out of comparison, even if I spec it to be comparable with the first three offerings... and this not even considering I can't order it with a dedicate video card. That said, my question are the following. Is there someone that would out of pure kindness explain to me what the technical and practical differences are between the fourh-generation Intel i7 processors and the newer, sixth-generation ones that one can have if he gets the 2016 MPB? From what I appreciate, the RAM of the newer models is rated at 2133 MHz versus the 1600 MHz of that on the older models. Anyway, does this imply a difference in operational smoothness or some other peculiar advantage in choosing the 2016 MPB, which has the 2133 MHz-rated RAM, versus the 2015 model, which sticks with the 1600 MHz one? Since I don't know jack about GPUs, may I ask you which performance and usability differences should I come to expect between a Radeon R9 and a Radeon Pro? Where are those products located in the product range of AMD? Since I need those ports and I don't like the idea of dongles hanging around my laptop and my backpack (neither I think they would last a lot being displaced all over two different hospitals and my house), I think I would be more than happy to order the 4870- or 4980HQ-equipped Mid-2015 MBP in the 512 GB SSD version (a bump up in storage would be useful, since I store a lot of radiological images - and a 30 GB music library - on my current 256 GB SSD which is showing its limits). Other than that, I feel really comfortable in buying a product I already own (convincing form factor, classic keyboard, ports, same excellent display) with upgraded internals and even more solid performance, but on the other hand I don't want to miss out new or important features. I don't make a point about getting the last possible technology... wouldn't it be nice to get sixth-generation versus fourth-generation processors? Yes, but when a seventh generation is already on Intel's website I understand that this will be, as we say here, a fight against windmills. And even more important than that, I'm not buying the most recent products if I don't know or understand the technical differences between them and last year's, and am not able to appreciate the added performance from with my day-to-day work with the computer. Thank you for you time, have a nice day!