Weight. A 3" or wider strap is a really good idea. Aria used some serious bits of tree when they made these - ones with a fancy/strong grain will probably weigh a bit less; if the grain is boring & very straight then the weight's likely to be more. They didn't muck about with the hardware either - the bridge is a big lump of cast brass.
I have to make a point, and sorry for the resurrection

I've owned by far two Aria SB1000, one from 1979, one from 1980 (I still have this one, it's my favourite bass), and actually the woods aren't that heavy!
picking up the 1980 bass, the overall wight is 4.7kg (10.36lbs), which is a bit heavy, but like my Music Man Stingray from 2004.
I dismounted the hardware and:
1) the brass plate on the back, covering the electronics, weights 200g (0.44lbs)
2) the enormous brass bridge (that goes deep in the wood) wights 300g (0.66lbs), more than a Badass II
3) the tuners weight 70g each (0.15lbs), for a total of 280g (0.61lbs)
in fact, the reissue model from 2020, with lighter tuners, lighter bridge and plastic covers on the back weights an average of 4.1kg (based on what I found online), some 4kg, some 4.2kg.
an average Fender American Standard weights 4kg/4.1kg with light tuners as stock from 2008 and 2013 (even lighter).
so, in fact, the weight of the Aria SB1000 is not in the woods, but mostly in the hardware, and only the back plate lessen the weight by 200g... which is insane
my '78 weighted 4.6kg, and I'm about to buy a 1985 (black wings) that weights also 4.6kg.
if I wanted to lighten it a bit, I could go to 4.4kg only switching to a plastic cover, or even 140g less with light tuners (which are around 35g each, so half the weight of the stock ones). so it would weight like an average bass.
I attached the pictures

the one with blue background is the '79, the green background (original case) is the '80, the black one is the '85
