I was trying to stay away from suggesting actual ring sizes, but my experience has been similar to yours.
A 50/34/24 did not shift well for me. Lots of skating up and down, not very reliable from ring to ring even with correct chain line and several different triple FD's.
Migrated to a 48/36/24 (12 tooth spacing) and that has worked well on several bikes. Right now only have one bike with a triple- the 83 Davidson Discovery- and that shifts well with that combination.