Buying a carrier device is usually a bad idea. Not only are bootloaders often locked, but the bloat and slower updates make an impact on usability for us enthusiasts. Fortunately, that’s not always the case.
Unfortunately, that’s exactly the case with the OnePlus 6T. The device that T-Mobile sells only comes in the $579 Mirror Black configuration with 128GB of storage and 8GB of RAM. If you buy from OnePlus, you can get the unlocked one for $30 cheaper with 6GB of RAM, upgrade to 256GB of storage, or go for the matte Midnight Black model.
Even worse, OnePlus says that updates will be delayed due to certification done by the carrier, and software betas will not work on the device. The bootloader will be unlockable, but only after the device has been paid off and has spent 40 days on the T-Mobile network. Lastly, travelers will be impacted because the device only has one SIM slot rather than two.
The moral of the story is: If you’re an enthusiast, don’t buy a carrier device. The unlocked model will work on T-Mobile just the same. If these problems don’t affect you, then go for it!