Somewhat off topic, what're Vaio users migrating to? I look every year or so to see what the current laptop offerings are, and nothing has convinced me to leave my 5+ year old Vaio.
The above mentioned "premium fatal flaw" in this case is the terrible internal wifi, but a micro-usb wifi has corrected that. I also fixed IMO the glossy display with a screen protector. Other than those two issues, I really like it.
When it's finally time to replace it I'll be looking at Microsoft or Dell. Maybe even Apple or ASUS. Probably not Lenovo, because they seem to be trying to destroy the Thinkpad brand. If I had to buy a computer right now without further research it would be the Dell XPS 13.
Have you tried the internal Wifi with a newer Linux distribution? I'm using Ubuntu 15.04 and it works great :) No disconnects, speed good be better though ...
Regarding a replacement: What do you think about the Librem 13? It's one of my favorites along with the Dell XPS 13 and the Lenovo X1 Carbon.
Related: This screen protector makes the glossy display usable outside: http://www.amazon.com/gp/product/B00HDTVJKQ
I'm really happy to see the Librem 13 nearing existence, but it's not ideal for me: i5 only, no back-lit keyboard. Up to 16GB and the matte screen is awesome though. The X1 Carbon 1st/3rd Gens are great, but Lenovo is being so bad recently.
That said, it seems like the next laptop I'm getting just might be this Surface Book, or the next iteration of it.
They just launched their Surface Pro competitor in the US: http://us.vaio.com/
(Typing this on the final version of the Sony Vaio Z, eagerly looking for a Skylake based successor...)