Jon made a good point about the legnth of the neck. I play bouzouki in GDAE tuning & a mandolin as well. You can realy fly on a mandolin but you have to take it slower on the longer necked bouzouki. But if you your 4 string & 5 string have the same legnth (some do)then both work well. Sometimes I do desire the plucked sound so occasionaly I will flat pick mine. That way I can go back to frailing when I want to do back up work. I really dislike a four string for back up. The extra drone of the 5 greatly adds to accompaniment as does the G or dbl.C tuning. But even then as much as I like the banjo I can't bear to hear it throughout every song or tune. Sully mentioned (in his book)needing a 4 string because of having to use different tunings I don't find this a problem as I only use the two mentioned.