Representing binaries numbers with explicit sign bit and the rest unsigned gets you an even better version of that; this is how floating point handle the sign.
I'm skeptical of value of ternary. The key behind the success of binary computers is that binary has great noise immunity; having a _single_ threshold is way simpler to get working than two or more. (Yet we do go there for NAND Flash, but note how speed and endurance worsen dramatically as thresholds are added).
The "most economical radix" is often cited but it's a red herring - it ignores practical concern of greater importance.
I'm skeptical of value of ternary. The key behind the success of binary computers is that binary has great noise immunity; having a _single_ threshold is way simpler to get working than two or more. (Yet we do go there for NAND Flash, but note how speed and endurance worsen dramatically as thresholds are added).
The "most economical radix" is often cited but it's a red herring - it ignores practical concern of greater importance.