I have used both, mounted at the same feed point height, with a switch to each antenna.
Depending on where I wanted to talk, and conditions, at times the 1/4 wave would out talk the 5/8 and sometimes the other way around.
It depends on feed point height, soil and terrain.
I was down in a steep little valley in the Sierras.
I have also used a 5/8 ground mounted (less than 12" off the ground) in open terrain with very good results.
1/4 waves with sloped radials are under rated a lot in my opinion.
73
Jeff