I had an interesting period of time today with a student who could/would not see the superfluousness of 'met up with' over 'met'.
Just out of interest, do you see a difference between the two?
I was trying to point out that 'met' is perfectly acceptable. and 'met up with' is two words too many.
Whilst from a purely linguistic point of view I would agree with you, nevertheless "met up with" implies some kind of prior arrangement, unlike "met" which suggest an accidental encounter.