I don't really need a computer....but I have to admit the nerd/geek/lots of excel spreadsheets with graphs part of me loves it and wouldn't be without it.

for me I have to have speed, trip distance, total distance, avg speed, trip time. I like the max speed and of course a clock is nice.

I do keep track of some of these on spread sheet, as much to record how my fitness is waxing and waning as anything....and because I have to have excel data, pivot tables and graphs