Depends on what you use it for and why.

It's a lot more convenient than using the number row, especially if you have to input a bunch of numbers at once. I find it rather handy for jotting up my budget, for example. I could do it with the standard number row, but the number pad is easier and nicer to do it with.

Also good for games that have a lot of hotkeys, like Minecraft modpacks. You get more buttons.