I wouldn't want the distraction of trying to look for some variable value while I was driving. I'd rather have the entire run displayed in front of me on a PC screen so I can zoom in for detail (calculate a real world C rating for example). I've even put my recorder between the rcvr and the batt to see what the servos are drawing.
The data served up by either system, logger or telemetry, is diff by nature and used for diff purposes. I can't see either system serving for the other's purpose, that would be a poor fit in either case.