While doing research for a new article on why GPS-based directions consistently seem to lead me astray, I asked a group of people who use and own GPS apps and personal navigation devices (PNDs) for products they recommend, as well as insight into the current state of GPS technology. Here are some of their likes, dislikes and other general observations about the market.\nBest and Worst GPS Products\nIn our survey of 10 GPS users, Google Maps earned more kudos (seven votes) than any other GPS app or PND.\nGoogle Maps is "accurate and reliable," says Rob Chamberlin, cofounder and executive vice president, DataXoom. "Google is constantly updating the interface, and I like that it interfaces easily with my other Google apps."\nAn excellent integrated search function is another plus for Google Maps, according to Samantha Boles, president and COO, Automated Security IS. "It automatically pulls addresses from my [Gmail] email or [Google] contacts. If I start typing Marriott, for example, it will pull up the most recent address for Marriott in my email and show me the address."\u00a0\n[Related: How to Get GPS Directions on the Go Without Using Your Data Plan]\n"I use Google Maps exclusively due to accuracy and convenience," says Simon of Rideshare Dashboard, who drives for ridesharing services Uber, Lyft and Sidecar.\nKwok admits that Google Maps isn't perfect, however. "Sometimes it wants me to make illegal U-turns. There was one time it wanted me to drive the wrong way on a one-way street. Luckily, I knew a detour, but it could have been dangerous."\nAs for the least favorite GPS navigation app, two users cited MapQuest.\nMapQuest led Chamberlin astray on many occasions. "The most notable story was in downtown Boston, when the app directed me to a road that had since been permanently closed," Chamberlin says. "I was late for an appointment, sitting in what had become a cul-de-sac, trying to figure out how to retrace my route and find a client's office." The experience eventually led him to embrace Google Maps.\nOthers have mixed feelings about their favorites. Heather Piper, co-owner, Thrill of the Hunt, a company that organizes themed scavenger hunts, says she likes Waze and its social components, but the app's directions aren't reliable.\n"Recently, I was in Virginia and the app told me to turn onto a road," Hunt says. "After turning, and then sitting at the light, it instantly changed its mind and wanted me to go in a completely different direction. This app has actually done this to me on many, many occasions. And when I add that a road is closed or there's a detour, it won't update and will take me back to the same location time and time again."\nPiper says a now-defunct Garmin PND was her favorite GPS product "by far."\nCommon GPS Gripes\n"GPS apps are only as good as their devices' GPS geolocation capabilities," according to Henry H. Harteveldt, travel industry analyst and founder, Atmosphere Research Group. "I've found with my Android OS smartphone that sometimes the apps can be way off. For example, a local transit-schedule app, MyBus, is rarely able to determine my correct location. I have to constantly correct Uber to determine my pick-up location." Harteveldt primarily uses Google Maps for directions.\n"My one gripe with all GPS navigation is the confusion and lack of direction when returning a rental car to an airport," says Jim Dailakis, an actor, writer and comedian. "They are seldom accurate, and you're better off relying on signs."\nAre PNDs and In-Car GPS Systems Obsolete?\nMany sources we spoke with say PNDs and dedicated vehicle GPS systems are no longer necessary, thanks to the prevalence of mobile apps for navigation.\n"I see absolutely no need for a portable device," Dailakis says. "I suppose the benefit of having one is that you don't incur data charges, but I feel as though cell phone providers are rather generous in that department these days."\nPNDs "just give thieves an incentive to break into your car," says Jose M. Lopez, a real estate agent. "It's also more hassle for the user, who has to store and sync that device, pay for map updates, or pay for traffic services. All that is available with a smartphone app."\n\u00a0"There's no longer any value in an in-car GPS system," Chamberlin says. "It seems like updating the software \u2026 is always a hassle." Phablets and other small tablets offer the same quality screens, and they're easier to update, according to Chamberlin.\n[Related: What a Trip to London Taught Me About GPS Apps and Navigation]\nCumberford says an older TomTom PND once got him and his fianc\u00e9 lost in California, and their car was nearly out of gas, but that was because he hadn't updated the device's maps. "This is where an app has the advantage, as it's much easier to update," he says.\nHowever, some users still prefer PNDs.\nReal estate investor and developer Brent Cumberford uses Google Maps in the office to locate places on a map, but when he's out driving he prefers a TomTom PND because he can affix it to his windshield for easy viewing. "It also avoids using up the data plan on my iPhone," he says.\nThere is still a need for dedicated GPS, according to Kwok, especially if you are travelling in a foreign country.\n"Google Maps and other GPS apps may not be available in Asia or Australia, while Garmin offers great international versions of their GPS," Kwok says. "Some devices have options to swap maps and navigation via SD card. Also, portable devices sometimes have larger screens and better UI polish than smartphones and apps."\n\u00a0Kwok also says his phone sometimes overheats when using GPS, so he prefers to use a standalone GPS device while driving for Uber or Lyft.\nWhether you use a GPS app or dedicated device, neither is a suitable replacement for common sense. "My number one rule for using GPS is to remember that it's just a tool to help you get to your destination, Dailakis says. "Wherever possible, use your brain first and the GPS second."