Personally I would go with the Teranis if you can stretch to the extra cash outlay. Not only does it have all the features you are looking for 'out of the box' but it's all round a higher quality piece of kit and has functionality that the 9X can never offer regardless of what mods you do.
Personally i find telemetry of great value. It can measure many parameters but the most helpful is battery voltage sensing. This allows real time motoring of both the main flight battery voltage and the voltage being supplied to the receiver and servos. Alarms can be set to sound when any voltage drops below a user determined value meaning that you will never again suffer 'low volt cut-out' of power.
There have been mentions of some 'problems' with early batch Teranis Tx's but no one seems to be able to provide any specifics, more just vague hear-say comments on non-specific 'problems'.