My acer c720p has a haswell processor, 4 GB ram and I'm working from ssd right now. You can dual boot into Linux and develop in rails, vim, x-windows is 3d accelerated. Virtualbox, vmware, libreoffice, postgresql, nginx - everything works. Linux is not as shiny as OSX, but it gets the job done.
That's good. I'm not trying to rally for OSX's cause as I develop on all platforms, with Mac OSX only being officially/legally able to be ran on Mac hardware which is why I didn't get a PC for developing on a Mac properly. I did build a hackintosh but found the hardware on MacBooks compelling when I saved up enough.
Do you supplement the internal storage with external? Is it a hassle? My Windows VMs are all 50GB+ so having tiny internal SSD storage is crippling.