I have only used this on a 3-day hike through the White Mountains, but am pleased enough to write a first impressions review. I did recharge the Fenix each night using an external battery so cannot comment on whether one charge holds ups over a three-day period.
Comfortable to wear even on small wrists; Logical menu tree; Easy to upload data to activity tracking websites
Must spend extra money to buy maps from Garmin; Illumination of screens is weak; but perhaps can be changed; am not sure