Is Mandolin a hard to learn instrument? I notice a lot of guitarist also play Mandolin... was wondering if the skills and technique required is similar to guitar playing..

Is it a lot easierfor a guitarist to learn mandolin as well? Whats the main difference in Guitar and Mandolin Playing??

The right hand stuff is similar (though not exactly the same). The pick attack is a little different (you have to follow thru to two strings). A mando is tuned in 5ths (vs guitar in 4ths) so that is a significant difference in left hand stuff, though some basic skills (eg hammer on, barre etc) re similar.

Unlike the guitar, mando is tuned symmetrically so all closed poition chords are movable across strings and up or down the neck.