Will a sata iii ssd work if i want to upgrade the ssd on my asus ultrabook ux31a?

Q. 128gb isnt enough for me. I want to double it but i dont want to cheap out on a sata ii ssd.

A. It WILL work, my friend, but the data throughput will be limited to SATA 2 speeds.

How well does an ultrabook perform in terms of heavy programming?

Q. Heavy programming in the sense multiple Visual Studio windows open at the same time as well as chrome and eclipse.

A. I don't know what the specs are of the ultrabook

Eclipse and visual studio are both memory hogs.
Try to get a system with as close as possible to 8 gigs of ram with either an i7 or i5

What are the specifics that makes an Ultrabook different from any other laptop?

Q. Im going to buy a new laptop soon and I want to understand if this is a superior type than any other or is it just some fancy named laptop?

A. An Ultrabook is a higher-end laptop that's designed to reduce bulk without compromising performance. You'll recognize an Ultrabook-style laptop by it's very thin, (typically) unibody chassis (meaning the entire chassis is made of a single piece of metal as opposed to several parts that detach), omission of optical drives (CD/DVD), and occasionally the omission of other adapters, like Ethernet, FireWire, or USB. If you're not concerned about the thinness, weight, or aesthetic of an ultrabook, you might not be able to justify the price, which is typically up to several hundred dollars more than a similarly-featured standard laptop.