Just before writing this, I spent a half hour noodling around on a piano a friend lent me for a while.
Reminded me of years ago, when I was about 6 years old and taking piano lessons...
Anyhow, piano is a cool instrument, no doubt about it.
BUT - and I say this knowing that some are going to disagree with me - I still like the guitar better :-).
Of course, personal preference can play a role, as well as the fact that I actually know how to play a guitar, while I can barely do anything by comparison on the piano, but I do have another reason too:
On a piano, if you want to play a C major scale, just start on a C note, and play every white key after that, and you'll end up with a C major scale.
As soon as you leave the key of C, you need to start omitting some white keys, and including some black keys.
The specific ones vary, depending on which key you're in.
So, you have to remember a unique scale pattern for every single key.
On the guitar, it's not like that at all.
On the guitar, you can learn the major scale pattern, and apply that exact same fingering pattern to any key your little ol' heart desires...
If you want C major, no problem, just start that pattern off on a C, and you'll have a C major scale.
So, you COULD say that on guitar, you have only one seventh as much memorizing to do as a piano player does!
At least, that's how I look at it.
And when it comes to learning your guitar scales, I always recommend people start out right here.