I'll repeat what others have said..... This comes down to pure curiosity and enjoyment of the sport.
You stated in your first post that the Viscaria suits your play style a lot? If that's the case, why change?
I'll assume you are an attacker (given your rubbers and blade), but obviously I have no idea about your level.
If you have decent technique, you'll not really notice much difference at all.
The HL5x looks to be a touch quicker than the HL5 due to the thicker core.
But I think you'll find the HL5 to be slower than your Viscaria due to the "inner carbon" - I'd imagine the HL5x will also be a touch slower, but could be similar in terms of speed.
Ultimately, if you are playing well with the Viscaria, and want to improve or keep winning.... You should stick with the Viscaria, or something similar (there are enough Viscaria clones to chose from.... TB ALC, ZJ ALC etc).
If you are finding the Viscaria is a little quick, then go for the bog standard HL5 (I'd ignore the HL5x).
The adjustment isn't huge either way (if you have the technique), but you'll find the reaction shots at crucial times in a match will suffer if you are used to the Viscaria and opt for the HL5.