Mark, many moons ago I played in the Italian Open, using the small Dunlop 65 with blue numbers. I found it easier to drive with (harder to fade and hook), went 10% further on average, putted great (seemed denser and held it's line), and was easier in the wind regardless what direction. I used both sizes in the Bahamas in the late 60s and early 70s. The small Titleist and small Penfold were pretty useless as I recall, but the pro version of the Dunlop 65 was good. As noted, it was tougher to chip with, and nestled down too much in bermuda grass. UK golfers didn't like the "big" ball, but Americans loved trying the small ball.
In summary, the small ball played about like the new balls!
In the 70s and 80s I noticed the great Moe Norman always had a ball ring, and used it on every ball he played. "Some don't fit through, good downwind. Some fall right through without touching, good wind balls!". He used to say Titleist were pretty good, Dunlop Maxfli and Penfold had lots of over or under sized balls at the time. Of course TOP-Flite and DYNA MAX came out with their solid core balls and now most balls fit a mold (like the plyers hitting them).