Differences SX3 and K1

[Bigdawgracer]

Hi guys,

Just coming back into the fold after years (20!) away playing with full-size stuff.

I always used to be a Schumacher guy and had a variety of Cats, Bosscats etc.

I'm thinking of getting a Schumacher 4wd.

What are the differences between the Cat SX3 and K1?

Do they share parts or is the K1 all new?

Advice appreciated.

Thanks for looking in!