I've had the Viscaria longer than the AZXi. But I found the AZXi to be a bit slower in comparison to the Viscaria. I have tried the same 2 rubber combinations on both to eliminate that variable. Combinations of both tensors and tacky rubbers were used. I found tacky rubbers were especially slow on the AZXi compared to the Viscaria; I have used Nittaku H3 OS, H3 neo & nat BS. I'm still trying to figure out my perfect blade/rubber combinations after an 8 year break from the game. I have been playing again for the last 2 years, and I'm still not 100% comfortable with my current setup. It could also be FOMO because the blade/rubber market & variety of products is overwhelming! So I'm still experimenting, and trying to figure out what suits my style.
I found because the Viscaria's first two layers are Koto, then ALC it's physically a lot harder layer than the limba, 3rd layer composite of the AZXi. I used to have an acoustic (limba outer all wood blade), but found that too slow as well for my looping style. Or maybe I just got used to the hardness of Viscaria?
I've also read (on a similar forum) that some people can be are more sensitive to the feeling produced by koto or limba.
Would love to hear other peoples thoughts on this.