The ssd on the logic board on the touchbar MBP is is bad news for future reliability. The only parts I expect to go bad are the ssd and the battery, these have a set amount of use before they need to be replaced.
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Yes, I agree on the SSD & battery.
As a seasonal present to myself I just bought a transcend 240GB SSD to update my 'longevity' Mid-2011 11-inch Air [2/64] The 2Gb RAM is working perfectly on Mavericks tho' with the new 'triple speed' SSD I'll be able to try El Capitan and get the kernel security rewrite, I think 2GB will still work fairly well due to the fast swap handling. My present hasnt yet arrived, but the rest of this 11" MBA is a very solid machine, great screen, hinges, very cool.
I disagree slightly with some group thoughts that the apple laptops will eventually be 'unusable', (I still have a PPC G4 Macmini running tenfourfox)
http://www.floodgap.com/software/tenfourfox/ with 1GB RAM & 40GB HDD. Enthusiasts will hopefully keep niche applications open, provided the underlying h/w does not have 'lemon' issues.
I consider my quad Core-i7 15" MBPs which have the very fragile GPU heatsinking, as an apple 'lemon' (batteries also often balloon on failure ~ 3 years) The original MBA is also a bit of a lemon, with another expanding battery and the unique form-factor 1.8inch HDD. Although one of my friends has chosen his quad-i7 MBP17" for his long-term project., he's now looking for upgrades to 4TB SSD in his machine, but he has also had to replace his mobo for thermal/gpu reasons.
I have personally settled on core-i5 CPUs as the 'sweet-spot' for processor power. Although a recent computer might seem better, around the $1K, currently my 2GB MBA4,1 has been seen for just $300, the eBay 'refurb' whole mobos with a 4GB RAM update for it are sometimes around the $150 level (RAM upgrade by changing the mobo!), but I chose to throw in a new "JetDrive 500" SATAIII 6Gb/s Solid State Drive Upgrade Kit for MBA for the $150 instead. (it unfortunately costs ~180 euro, this side of the atlantic)
I think the end-point for my apple h/w will be to run linux-mint if apple do discontinue OS upgrades prematurely!
My kids are now getting refurb lenovo x220/T430 series for college, running Mint17.2 [& Win10 occasionally,] due to my reliability worries/$$$-issues with apple. I did put 16GB RAM in one of the lenovo, but this was for Virtual machine work. 8GB is plenty for average use.