All depends :
Is a single bass giving you everything you need from it?
Matches your personality and sound?
Is versatile enough for the styles you want or need to play?
I can honestly say yes to this.
I currently own only one bass. Bought it new in 2000 has been my main gigging ax since day one and the only one I own for about 8 years now.
However, I will admit that it would not bother me to have a twin as a backup.
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