I haven't saw your post, sorry
so what I can tell you is that the virus is fastest , normal, it's smaller...
the bigger difference is that it's harder to make one pop yoyo with the Nazko, but they're great in two moves...
If you have the original bridle settings on your virus, it turn wider than the Nazko...
if you know those kites, I give you an example... it's like you compare the Nirvana and the x-masque...