When Sony sold off its VAIO computer division, I picked up a Sony VAIO Tap 11 SVT11213CXB on the cheap from Best Buy. The default configuration of the SVT11213CXB is a Pentium 3560Y, 4GB memory, and 128GB SSD. While the 128GB SSD is just enough to get by, it really is too small. I personally recommend at least a 240-256GB SSD. It's the bare minimum so that you can install software and have space for personal files. A 128GB disk is only enough for software and requires constant management to make sure you're not filling up the disk.
That said, I decided to go BIG and put in a Samsung EVO 840 500GB SSD into the Sony VAIO Tap 11. I followed the Sony published teardown video of the Sony VAIO Tap 11 and it's definitely more precarious than the video makes it out to be.
See the Sony VAIO Tap 11 teardown here on blog.sony.com.