My problem with Garmin and their bike computers is that their customer service is extremely poor. I bought one that didn't work properly. Garmin bounced me around with nonsensical and wrong answers until I gave up. Fortunately I had purchased the unit from REI. REI has outstanding customer service. They just replaced the unit. The new one worked just fine and I am a happy camper.

Recently I wanted a wriist mounted GPS and Garmin had a "sale". I bought it from REI again. Twice snake bit this one didn't work correctly either. Customer service again reached down into the dark pit. But, I didn't play with it very much. After the umpteenth email the last of which weren't even answered I just sent it back to REI who refunded my money. Interestingly about a month after I sent the unit back I received a reply to my last email conceding there were problems and they didn't have a clue what the problem was.

If you HAVE to buy Garmin buy the cheapest you can and buy from a company with a good return policy. Garmin's quality control apparently is poor and the customer serice is worse. That is in stark contrast to their aviation products.