If acoustically it makes no difference between a solid silver body and a plated one, What is the benefit of buying Azumi's 3000 over the 2000? Both have an altus z-cut head, but I am led to believe the 3000 has a larger hole.

the sp1 springs are smoth and faster than common stainless steel springs used in the 2000 series

Does your old flute have wear on the spots where you hold it? (i.e. fingerprints, lip stains, etc.) Having a silver body makes it easier to remove any fingerprints, hand gunk, surface damage, etc.

Also, will you ever sell this flute to upgrade again? If you think that is a possibility, I would go with the 3000. They have better resale value.

If the cut is the same, there is no reason to 3000 emb.hoe being bigger than 2000.
There are tiny differences even when you compare quality instruments of the same model, but nothing that you would notice just looking at.

The basic difference between an instrument that is plated and other solid, is that this later will last longer. Plated instruments suffer more with usage and aging.