In terms of capabilities between ThinkScan Plus 7 vs ThinkDiag, there are no differences. The cost difference is in the cost of the hardware itself... With the dongle, you have to use your hardware/phone/tablet/pad and with the other one you don't.
In fact there is no difference in diagnostic capability and variant coding capability between ThinkDiag and the more expensive Launch x431 Pro Pad V.... The difference is in the flashing capability and access you pay for that to Launch... But when it comes to sprinters, Launch does not really have a database of firmwares or updates that can be flashed on sprinters. For sedans and SUVs they do, but not for sprinters.
I have compared ThinkDiag vs ThinkDiag 2 vs Launch x431 Pro Pad V + J2534/DoiP VCI (have access to all 3) and there is no difference between them when it comes to diagnostic and variant coding capabilities for sprinters.
In fact there is no difference in diagnostic capability and variant coding capability between ThinkDiag and the more expensive Launch x431 Pro Pad V.... The difference is in the flashing capability and access you pay for that to Launch... But when it comes to sprinters, Launch does not really have a database of firmwares or updates that can be flashed on sprinters. For sedans and SUVs they do, but not for sprinters.
I have compared ThinkDiag vs ThinkDiag 2 vs Launch x431 Pro Pad V + J2534/DoiP VCI (have access to all 3) and there is no difference between them when it comes to diagnostic and variant coding capabilities for sprinters.