It depends on what you're planning to do with it.
If you want small games you can already play them on a psvita or 3ds with a better comfortability.
If you want some better games handheld surely its the way to go, but do you want to play stuff like metro handheld?
The steamdeck is already outdated and doesnt run new games, take that into consideration.
So if you want to play something like alan wake 2 than tough luck.
I think the steamdeck is really only worth it if you want to play some ps3 or gamecube games while riding a train, or you want to escape family christmas and shit like this