I haven't really noticed any differences with sound. The tips have roughly the same bore diameter, skirt OD, etc.
The differences between the AZLA and Auvio on the BL-03 is more how it fits the Blon nozzle:
1. AZLA fits the Blon nozzle more securely. The Auvio still fits the Blons very well, but the AZLA locks onto the Blon nozzle with death grip.
2. The core on the AZLA is a few mm longer than the Auvios, so the tip sticks out a few mm longer. This can potentially address fit issues with some people who feel the Blon nozzle is too short.
I can post pictures if it would help to see.
Note this is with M Auvio and SM AZLA tips. It's possible that other sizes are different. For example, when you look at the core of Starlines, it actually sticks out of the skirt on S, is even with the skirt on M, and sticks inside of the skirt on L.