Glancing at the Scanning Sense (Sonar) in 4e, what you describe seems to make sense: base 20-point ability can be enhanced a lot, while Blindness is [-50], so it's possible to make a combat-good sensor (at least at short ranges) from that while still saving some points. Whether that's a fair trade for the downside of not distinguishing *visual* stuff will of course be a matter of some debate.
Vibration Sense can probably be enhanced even more efficiently, but requires some non-obvious choices, and is worse for noncombat resolution.