eTrex Summit (and eTrex) are designed with a new "non technical" GPS user in mind. It is designed with simplified controls, simplified and reduced features and generally seems intended for a "new GPS user" with no GPS experience.
另外，像文中提到的“On the other hand, the "not included" features we like to use in a more standard version GPS such as the G-12xl fill a pretty good list. They include: external antenna port, trip timers, cross track error, POI/city data points, pan & scan, waypoint averaging, multiple user adjustable screen formats, internal wide range voltage regulator, and is also missing a range of additional display screens and features compared with (say) the G-12xl, G-12Map, etc. ”