Two different animals if you ask me.
Carvin is a pretty high end, USA made boutique quality bass.
MTD Heir is made overseas (Korea? China?) and would need at least an electronics upgrade to get in the same ballpark as a Carvin. They are some of the better mass produced overseas basses, but still are mass produced overseas.
Carvin wins here by a mile.
Fuzzrocious Club #194
Brubaker Brute Squad #18
Spector Club #224 (USA NS-5MM, NS-2J)