For its third generation smartwatch, Apple added cellular connectivity as the marquee new feature. Otherwise, the Apple Watch Series 3 looks and functions almost exactly like its predecessors, albeit with a faster processor and a new altimeter sensor. The price for the cellular-connected model starts at $399, plus a $10 per month wireless plan from one of the major carriers. A non-cellular Series 3 starts at only $329 versus last year’s Apple Watch Series 2 starting price of $369.

The new Apple watch’s ability to connect to LTE mobile networks on its own was supposed to make the device more useful when owners want to leave their phone at home, say while on a run or at the beach. But reviewers like Joanna Stern at the Wall Street Journal and Lauren Goode at The Verge found their review units often had trouble making the mobile connection.

“There’s this moment in “Dick Tracy” where the fearless detective, chasing down a villainous gang, taps his magical wristwatch to call for backup,” Stern wrote. “Then, realizing the battery is down to 8% and that cellular isn’t connecting, he ducks under a desk to find a power outlet and futz with the settings. Poor Dick, he upgraded to the cellular version of the Apple Watch Series 3.”

Problems with Apple watch connectivity cropped up on three different pre-production models, across two states and on two different carriers, Stern said.

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“On more than one occasion, I detached myself from the phone, traveled blocks away from my home or office, and watched the Watch struggle to connect to LTE,” Goode noted. “It would appear to pick up a single bar of some random Wi-Fi signal, and hang on that, rather than switching to LTE.”

Apple (AAPL) sent a statement to Goode explaining that it had found a bug in the Series 3 watch’s connectivity function that it planned to correct. “When Apple Watch Series 3 joins unauthenticated Wi-Fi networks without connectivity, it may at times prevent the watch from using cellular,” Apple said in its statement. “We are investigating a fix for a future software release.”

For reviewers who got the Apple watch’s cellular connection working, battery life became a challenge. Wired’s David Pierce said the Apple Watch Series 3 battery lasted all day with normal use but plunged to five hours or less when he used the device’s LTE modem much.

“Apple rates the phone-call-on-LTE battery life at one hour, which matches my testing,” he noted. “You won’t replace your iPhone with a Watch because it just doesn’t last long enough. It’s more for the times when you’re on a run and need to make a call.”

Reviewers have also criticized a cosmetic change in the Apple Series 3 watch. Although the device is almost precisely the same dimensions and weight as earlier iterations, Apple decided to make the circle inside the watch’s side dial bright red.

Long-time Apple watcher and blogger John Gruber said he couldn’t understand why Apple would choose the bright red color, which doesn’t match even some of the colors of watch bands Apple itself sells.

“There’s no way to review this watch without mentioning the red dot on the digital crown,” Gruber wrote. “All cellular equipped Series 3 watches, including all the stainless steel models, the ceramic Edition models, and the Hermès models, have this red dot. I don’t get it. It’s not that it looks bad in and of itself, but it draws unnecessary attention. I would much prefer this watch if it were black. Also, red doesn’t go with everything, and a huge part of the fun of Apple Watch is swapping bands. Apple sells a lot of watch bands that clash with the red dot.”

Gruber ultimately found the device useful and did not experience connectivity problems. He also praised the quality of phone calls on the new Apple watch.

“Audio quality for phone calls on the watch is very good,” Gruber wrote. “People I called via the watch said I sounded great, and I could hear them loud and clear. And all of my testing of phone calls on the watch took place mid-day on busy city streets — full of traffic and pedestrians — here in Philadelphia. People won’t know you’re calling them from your watch if you don’t tell them.”

The Series 3 also won over a true watch aficionado, Ben Clymer at the watch industry web site Hodinkee. 

“I don’t know that I ever would’ve guessed I would say this about a smartwatch, but Apple Watch Series 3 might make your life better – you’ll be less connected with the digital world and more connected with the real world around you,” Clymer wrote. “In the few days I’ve been using the Series 3 Edition as my only communication device, I’ve found myself checking Instagram less. Texting less. Dickin’ around on the web less. I use the watch to text or make phone calls when I need to – and that’s it. My definition of ‘need’ has changed completely – and frankly I don’t miss having my phone in my pocket at all.”

Another fairly positive review came from Buzzfeed’s Nicole Nguyen, who declared the Apple Watch Series 3 the “best smartwatch I’ve ever used” but explained that since most wearables were pretty awful, that wasn’t a great compliment. And she wasn’t too impressed with the new watch’s battery life, but found the device particularly useful for its fitness tracking functions.

“The Apple Watch Series 3 is a decent smartwatch, especially for athletes, as long as you’re willing to accept some of the tradeoffs (battery life for compact form factor, Apple’s own apps vs. third-party offerings),” Nguyen wrote. “The new cellular feature is great for leaving your phone behind during workouts (then taking an Uber back or stopping at Whole Foods for a refueling snack).”