SD Cards: Which one is right for you?

I was reading about the 5D Mk III today and came across something interesting from Jeff Cable's (excellent) blog. Apparently Canon didn't make the 5D's SD card slot UHS compatible. (UHS stands for Ultra High Speed - see this for specifics.)
This means if I put my UHS-I 95MB/s SD card in a 5D Mk III, the buffer will clear at 20MB/s. Not great.
However, this is old news - the original post is from June 2012. If you're a 5D Mk III owner and you haven't come across this yet, go buy a CF card :p
However, it did get me thinking. If it's not supported on a pro body like the 5D, it's not going to be supported by my lowly 550D, either. A quick test confirmed this - the buffer cleared in exactly the same time (6s) using a 90MB/s card and a 45MB/s card, meaning the speed limit is somewhere below 45MB/s. I suspect it's 20... :(
So why spend the extra money on fast SD cards? It'll take you less time to back up your photos. Or will it?

A different perspective

Over the past few days I've set myself the challenge of trying to interesting silhouettes. I got the idea when I was out in the evening with my camera and I saw this:

Not the most amazing image I've ever taken, but I realised I really liked the shapes of the rooftops, trees and the lamp post against the orange-blue sky. So I decided to mess about and try to get some more.