I've enjoyed having the computer on my bicycle, it's a "very simple" unit, mainly I like to know how far I've gone and what my total mileage is. LOL, it's also fun to check out how fast a bicycle can go with a serious downhill run!
I'm strictly a rec. rider, not into training and on some of the bigger hills, I'm glad I "can't" check my heartbeat! :O My wife has no use for a computer at all, she just want's to do "easy spinning" and enjoy being outside, (she works 4-5 12 hrs. days in a office). The only reason I'd "upgrade" would be to get the "wireless" version of the $20 computer I've got now!