Apple’s ultra-premium iPhone XS flagship phones hit stores last Friday, and after several days of testing, some users are reporting that the devices are falling short of their marketed specs. This year’s complaints: disappointing battery life, even on the larger iPhone XS Max model, and performance issues with both cellular and Wi-Fi connections.

As was discussed in our review of the iPhone XS and iPhone XS Max, both phones feature large batteries, with the Max surpassing every prior iPhone in raw battery capacity. However, the devices also have some of the largest screens, most powerful processors, and fastest wireless chips ever found in iPhones, all of which can contribute to draining power more quickly. Our review noted that battery performance of the new phones did not appear to be up to Apple’s claims, with the XS seemingly falling a little behind last year’s iPhone X, rather than exceeding it as Apple suggested.

A web browsing test by Tom’s Guide quantifies the issue, stating that both the iPhone XS and iPhone XS Max fell short of the iPhone X’s 10 hour and 49 minute web battery life, with the smaller model hitting 9 hours and 41 minutes, and Max reaching 10 hours and 38 minutes. The publication opined that “the iPhone XS and iPhone XS Max simply don’t have the staying power of the best Android phones,” pointing to Huawei, Google, Samsung, and OnePlus flagships with longer run times.

As Consumer Reports and other publications have discovered, however, battery testing of new Apple devices can be challenging: There may be bugs in day-one software, and the devices may quietly run indexing and other background setup processes that disappear — and stop draining the battery — over the first week of use. That said, Apple’s proclivity for prioritizing device thinness over battery life is well-established, so these issues might persist with the new iPhones.

Separately, a growing number of users on Reddit and other discussion forums have reported cellular and Wi-Fi issues with the new iPhones, generally but not exclusively focusing on two areas of concern. On the cellular front, some users on the edge of cell tower coverage say that they’re seeing reduced cellular signal strength, speed, and ability to maintain stable connections. Other users are complaining of connectivity and strength issues with 5GHz Wi-Fi networks.

In the absence of insight from Apple, which we’ve contacted for comment on the complaints, users have theorized that the problems relate to the use of Intel rather than Qualcomm modems, new wireless antennas that are lower-powered than before, or otherwise defective hardware. Historically, however, Apple has resolved similar issues in past iPhones by simply updating either Wi-Fi or modem software.

Apple typically responds to early user issues within several days of initial press reports, so we expect to have an update on at least the wireless portion of this story soon.