I've been playing both for the past 40 years and interchange freely. I think once you get used to it, you'll have no problem at all. Chords and scales are somewhat more logical on mandolin than a normal tuned guitar. The difference in scale length is a shock at first but easy to get used to. I have fairly large hands and a guitar with custom wide neck but my mandolin has a fairly narrow neck and its no real problem in changing.

I wouldn't necessarily say one is easier than the other at the highest levels of skill...both have their particular challenges and techniques, but both are great fun to play and the essentials of the mandolin are fairly easy to pick up.

Peace

moo