Xiom stradivarius vs Bty Viscaria

They are very similar.  It is a question of taste which one you prefer.  I like the Viscaria better because of the handle shape.

OTC is closer to a Viscaria than the Strad.  It has been a few years since I hit with a Strad and I only owned one of them so don't want to say a lot more, but all three blades are intended for the same kind of player.  The blade compositions seem quite similar -- koto topped arylate carbon (or aramide carbon in the case of Strad).  Those fibers give you pretty similar playing properties, with muted feel and vibration absorption, and large sweet spot.  Handle shapes are different.  The DTC cheaper and so a great deal for the money.  All three have impeccable build quality.  Switching from one to another is not going to make you a better player, but one thing to keep in mind is Viscaria only comes in FL.  You can get the Strad and OTC in three handle shapes.  You could order any of the three and end up with a really great blade.

gd insight into people's opinons! I would say strad is a bit more stiffer,faster and less flexier than viscaria? Would anyone agree?

I think that is correct but not hard to switch from one to the other.

I really liked the ST handle of the old gen Stradivarius. Bigger than BTY ST and squared.

What does the old generation Strad look like? I believe i would have a new one.