According to GSMArena, in this article, the T-Mobile (USA) variant of the OnePlus 6T is running a different, carrier branded, firmware to the Global models. Whilst the phone can be carrier unlocked after 40 days... "Also, T-Mobile can unlock your phone and let you use it with other carriers as long as you've been connected to their network for at least 40 consecutive days and you've paid off the remaining balance before the contract ends." The T-Mobile (USA) variant firmware has a couple of non-removable bloatware apps as well as some of the global model's apps removed, Quick Launch, OnePlus Laboratory, Smart Boost, etc; and a carrier locked bootloader that will prevent users from partaking in the OnePlus Open Beta programme which allows users to receive new features and firmwares, sometimes, months in advance... "And now some bad news. T-Mobile OnePlus 6T devices won't be able to participate in the OxygenOS Open Beta program and uninstall the additional software that T-Mobile pre-loads. On the other hand, the bloatware is pretty limited compared to other devices. We are referring to the Unlock app (for network unlocking) and the T-Mobile account manager app. According to a Reddit post, there's a way to uninstall the other two apps: Name ID and Visual Voicemail." Updates are likely to be a lot slower to the T-Mobile (USA) variant as they will need to be adapted for and certified by the carrier first and we all know how well that works with other phone manufacturers. So, whilst T-Mobile (USA) variant owners will receive a slightly subsidised phone it will not provide the stock OnePlus experience that the global model offers. I predict that once some T-Mobile (USA) variant users realise this, there will be a wailing and the gnashing of teeth that we have witnessed over the years with other U.S. carrier models. Bottom line... "If you want the full, unfettered, OnePlus phone experience... pay the full price and get yourself the Global model."