Handheld GPS units tend to be smaller and more compact so that they are easier to carry around. This smaller form factor often means that manufacturers cannot put every useful feature that they would like into the handheld GPS. There has to be a tradeoff and so some features are left out while others are included. Looking for and spotting the features that you want is important.
Expandable memory is a key feature to look for in a handheld GPS for a couple of reasons. First, a handheld GPS can be used in a variety of situations from hiking to boating. Expandable memory slots allow you to swap memory cards, rather than have to save over data each time that you want to use the GPS differently. Second, due to their smaller size, handheld GPS devices can only hold so much so that memory space is often a premium feature. Some devices have a set amount of memory and you will have to delete information in order to save any more.
The compass is another feature to consider. While most handheld GPS devices come with a compass, there are two types of electronic compasses. One type can only determine your heading if you are moving. The other type can determine your heading regardless of whether you are moving or standing still. Most devices these days have the more capable version, but it is always best to double check to make sure what you are getting and that you are happy with it.
Other miscellaneous features include positional information such as elevation, ascent rate and descent rate. Trip odometers, moving time, average moving speed, and other information are sometimes tracked by the device. Looking for features such as these is important if you plan to use the handheld GPS when you go bicycling for example, because it allows you to keep track of your progress from week to week.
