There are quite a few things that one should take into consideration when looking to buy a GPS enabled running watch. The most important thing to think about is the amount of money that you want to spend. From entry level watches at around $150 to more expensive watches with touchscreens that cost more than $400, there is a GPS watch that should fit any budget.
Another feature to take into consideration is the weight of the watch. Most watches can become irritating to wear if they weigh more than the watch that is currently being worn. Of course, this might vary from individual to individual, but for the most part, runners don't mind a watch that weighs a couple of ounces more than their current watch.
Software and interface are another point to consider. How easy is the watch to read while running? Are the numbers on the screen large enough and bold enough to glace at while running? Also, most runners would like to download information from the watch to a computer. USB connections are common ways to connect and/or charge the watch. The software and computer interface are important factors to consider too. If the watch works great, but the software on the PC or Mac is lacking, then it might discourage frequent use of the watch. A quick look online can show what the interface looks like before you ever spend a penny.
Not all GPS receivers are created equally, and the ability of the GPS running watch to quickly lock onto the current location can make or break the user experience. While runners might stretch some or jog lightly before starting the actual workout, no watch should take more than a couple of minutes to provide accurate information to the user. Also, look to see how well the GPS running watch retains a strong GPS signal while moving under trees or in the shadow of tall buildings. Sometimes a strong cloud cover can disrupt the GPS signal to the watch. Hardware plays a part here, but how well the software is optimized to the hardware can make the difference between a run in the rain being recorded accurately and missing half of a run's data.
Keeping these factors in mind should ensure that your next purchase of a GPS enabled running watch will be a positive one. Good luck in smashing that PR and enjoy your new watch.