I call shenanigans - latest OSX and XCode running on a 2008 Macbook right here on my desk. I plan to get 10 years usage out of this machine - that's value for money right there.
Refreshing current Apple computers won't be that easy. Even if you are capable of opening it, compatible M.2 drives won't be easy to find and you won't be able to swap soldered RAM. I'm not sure that my 2015 rMBP will be able to serve so long as that T430s will.
I wish Apple made their pro products more bulky so we can upgrade the hardware and let the air products be the sexy, thin ones for Starbucks hipsters.
That being said, Apple has gone to pretty crazy lengths to ensure that it's modern OSes work on legacy hardware; I was a bit shocked to hear from my parents that they were able to install El Capitan on my dad's 2008 iMac, as I was wary about putting it on my 2012 Macbook Air due to performance concerns. I don't know if this was a conscious decision by Apple to cater to the idea of "Apple = Longevity", but it's very nice to know that a single purchase takes you pretty far. I think Apple could take it a step further and really win over more people if they added the millimeter or two to the Pro line and allowed for the upgrades.
It's really a back and forth thing for me; on the one hand, I wish I had more options and the ability to customize later on. On the other hand, since ~2010, the appliance like nature of the portables has worked so seamlessly that my only complaint comes from the lack of an option to upgrade, not the need for an upgrade. For my previous Apple laptop, my own incompetence when trying to do a repair hurt the laptop's longevity; had I not had butterfingers when working on the insides, I'm sure that I could have had another 3 years with my already 5 year old Macbook.
Of course, with a Windows PC, you've got a variety of options, and can buy something that is actually upgradable, rather than being locked into what Apple deigns to give you.
When I bought my MacBook, 4GB of Ram were plenty but it is not anymore. Chrome takes to much ram and with 16GB, I don't have to worry about anything. Furthermore, apples new laptops are all dual core (until you buy the bigger one). This is also dealbreaker for me – quad cores are really awesome when using VMs. Sure a CPU cannot be updated on most laptops (and certainly not on apples but I can't blame really).
My point is that I'm afraid apples pro series has drifted into a state where their lifespan will shorten while the prices go up.
And apple's OS performs really good until you use third party applications that expect better performance then your sad 5-year-old MacBook.
It's just that, again, by and large with everything with the Mac line up right now, you throw something at it and you're good to go. Even my 2012' Air can do moderately advanced video editing in Premiere, the only real bottlenecks being local storage and the CPU taking a bit to render video.
The current line up is not a perfect solution for absolutely everything, and Apple's power option in the Mac Pro line is just unacceptable for most people, even if it does bring a lot to the table. But in most cases, Apple's line ups do extremely well for a large majority of things you'd want to use a computer for. I too would enjoy a quad core in the Air/Pro line, or at least the Pro line, though I suspect the issue is heat, and as I said earlier, I'd happily take a bit of thickness to accommodate a heftier processor.
I certainly don't endorse letting Apple tell me what hardware I need; I also don't have too many complaints with what they've given. Price exaggerations aside, I find the price tag for the Macbook Air/Pro lines appropriate for the base models, and comparable to other 13" sized machines with similar specs and amenities (for lack of a better word). Such is sort of the nature with Apple and being a long time user - there's a lot Apple does that bugs you, but at the same time, there is a lot of good you get with the hardware and the OS.
The 15" Macbook Pros are quad-core http://www.apple.com/uk/macbook-pro/specs-retina/