Originally Posted by Lingyis
guitar vs piano... based on popularity alone harder to gauge.

Just quickly picking up on that point. From past experience, I would say that the classical guitar is easier than the piano in the sense that (a) the musical standards (in general) aren't as high, i.e. you can get away with a lot more and (b) some of the pieces I used to play on the classical guitar are in ABRSM Grade 8 and it would take me many more years to get the to standard required of the Grade 8 pieces on the piano than it did on the classical guitar. (Incidentally, I was amazed to see Duarte's English Suite classed as Grade 8 guitar.)