I find that 8 is the max per day, because after 8 it's like I only showed 1 or 2 (the clients find it hard to remember them all, and even nicknames for homes don't work any longer...and even pictures taken don't help too much).
Comparing the properties is working well for me - picking the best and comparing others to that one is helpful to the clients, less confusion. Preview in the office (on a large screen TV) helps to cut down the amount of properties to visit physically as well.
There are several client groups: 1) Some have to hit more properties because until they see them all they don't feel they have enough of info to make their decision - the analytical type 2) Those that want us, as professionals, to cut their search time and really find them the best 3 properties (they trust us to deliver on their expectations) 3) Those that don't know what they want yet (office preview is great for that) - we have to help them figure themselves out 4) Yo-yos - will do it the way you propose, but are easily swayed by the relatives/friends who are not in real estate...so one day it's 3 and the other it's 8...
Best of luck,
CDPE - Certified Distressed Property Expert
Beachfront Realty, Inc.