The M114 was rapidly pulled from U.S. service in Vietnam and handed over to the ARVN, who didn't much appreciate them either. The front overhang of the hull in front of the track greatly limited it's cross-country mobility. It would be stopped by terrain that an M113 would easily take in stride.
By 1979 it had proven so useless in Germany that they were exchanged on a 5:3 basis for more M551 Sheridans, which had better mobility &, it was hoped, would be more of a deterrent by putting more MGM-51 Shillelagh Missiles on the defensive line.
The M114 was notoriously unreliable mechanically and can probably be said to be the only vehicle to make the small-block Chevy look bad (283C.I.). The commander of the 6th Recon Sqn. at Ft. Knox, who had 72 of them, did not have a good word to say about them.