Also I think it depends a lot on what fish you have in the tank, in my community tank I only have small fish where the largest is a Halequin Rasbora (apart from my BN Plec) so all my 100+ Cherry Shrimp sit out in the open because they see no threat from the fish. If you have larger fish that could eat the shrimp they are more than likley going to hide.
Last year I did put a pair of Electric Blue Rams in my tank and they ate a few shrimp and from that day onwards I didnt see many shrimp around, once the Rams succomed (died) due to my hard water the shrimp came out of hiding.