Buy the iPhone 5s or iPhone 6?

Okay so I'm kinda still deciding which device to buy, the iPhone 5s is a lot cheaper now since the 6 is out, but I'm pretty indecisive.
I like the square corners on the iPhone 5s, but I like the bigger screen on the 6.
Money? Well, the difference is only 100 dollars, I think my wallet will survive, aha.
I'm not a big fan of the rounded corners on the iPhone 6. I went to the Apple store, and it's incredibly thin, it almost slipped out of my hands!
But the screen size, it's kinda a huge deal.

What should I get?

I have the IPhone 6 and love it! I also had the 5s before. I would go with the 6! Much better device in my opinion. The details on it are much better and it has a better camera. Thats my opinion though.

I would go with the 5s. Pretty much the only difference between the two is size. Both phones have IOS 8.2 so mechanical wise they are the same. Physically, I much prefer 5s.

IPhone 6, just so you can definitely keep up with the new updates and all. For example, they just cut off iPhone 4 and everything before it in their most recent major update. Eventually it will happen to the 4S and the iPhone 5. It will be awhile before it happens to the 6. Best of luck