I like knowing how fast I'm going or not, real time and cadence, the rest don;t matter although ride time v real time always shocks me regarding time spend daydreaming at traffic lights, average moving speed 15.5mph (including slowing and stopping) yet it takes an hour to do 12.5 miles, I've been idly working this out in my head for weeks, even counting all the slowing and speeding times it means I'm stopped for 12 minutes in the hour, not sure I want to work out the full effect, reckon it's well in excess of 18 minutes n the hour used up on lights
how can you live without knowing that, get one, they're that cheap
(although mine wasn't, Delphi4 from operation support the LBS)