Barring is easy, but for beginners they usually deal with muting problems. And one reason is they will have a poor set up on their guitar ,with the strings to high or, the harmonics and intonation is off and they can't get thier chords to sound "pretty" or clean.
Transitioning problems take practice like anything else, however you can make things a lot easier by knowing different voicings and just like the keyboard you can work out economy of motion problems . Knowing where all your triads are all over the fretboard helps this problem also.
Guitar is a lot like piano in that you can use all types of inversions to help solve your problems with speed and effieciency . It is a lot easier to bend notes LOL ..... and the left hand seems to have more brains playing guitar than piano :lol: :lol: :lol: