I've used SwiftKey for the longest time due to this feature - where even if you're not using a dialer or similar function, when you press the number/symbol button, the numbers will appear in a numpad fashion on the left side of the screen. Virtually every other keyboard I've seen does the plain row of numbers at the top. Here's a picture of what I'm talking about, for those unsure:


Also, a secondary requirement of this keyboard is for it to scale properly with screen density adjustments. Swiftkey X Beta, for example, leaves me with a small keyboard in the middle of the screen with a large black box around it taking up extra space. Swype, on the other hand, still takes up over half the screen in general because it doesn't scale at all.