The 19X was designed to meet the specifications of the MHS contract, which is why they ended up with the short slide/long grip combination; the contract specified a certain barrel length and minimum magazine capacity.
As with most contracts like that, the manufacturer will produce the same pistol for civilian use, in this case all they changed was the thumb safety, which they left off. Again, the thumb safety was per the requirements of the MHS contract.
The Glock 19X was NOT designed with civilian CCW use in mind. It's sole purpose was to meet the parameters set forth in the MHS contract, which they did.
It was not intended to replace or improve upon the G19, it was designed to meet the MHS contract requirements.
Did I mention that the only reason the 19X was designed was to compete for an MHS contract?
What's up with the lanyard hole? What possible purpose does/would it serve?