Haro MTB for commuting and a LHT for everything else.
There are several Polar and Suuntos that do the same, let you download, etc. and use several variables for determining calorie consumption, such as age, weight, MHR, activity level and their own VO2 max calculation. The new Garmins (405x and 305x) are being marketed as using HR based calorie counters, but we won't know how accurate this is until they are released
Both Polar and Suunto do a better job at altitude both while on the ride and when saved to your desktop compared to Garmin