He prefers the watch-style computer over the brick form factor of the Perdix.
Having both the Teric and Perdix AI I too find myself in a similar situation of wanting a second Teric. This would streamline and standardize a whole lot - same interface, same charger, same strap, easily mount both to same arm right next to one another. Probably will sell my Perdix AI once Teric inventory levels stabilize.
It really comes down to a matter of form factor preference. Both the Teric and Perdix are great computers with the same dive capabilities with the exception of the Teric being able to perform double duty by being worn in and out of the water.
I can see the argument for one to be worn in the bar to demonstrate your diveriness but two? Wear two to the bar and they will think you just mugged someone. Ok, it is a bit of a hassle getting an arm with full size computer into a harness, you need to wiggle it for a second, but it is not so hard really. It already makes me wince when I have to squeeze a Petrel past a bailout cylinder to go into my pocket, if that were yet more money and not required to look fashionably used to be cool I’d cry everytme I pulled out a spare SMB.