Well, I own a Shuriken and a Standard, and they are my main guitars. I still use traditional guitar for practice, but thee pieces of equipment are definitely something incredible and when I play with other people, they're my go-to choice.
The pros are so many that it'd take a huge amount of words to describe, but what I find really game changing is the ability to switch tunings. The versatility of this instrument is just out of this world.
The con I see is basically just one: they are not user friendly, at all. There is a learning curve, and it's kinda steep.
Once you understand what you are doing, then there's no going back, this guitar is the ultimate instrument, you can create tones for any genre from good to great.
I hope there will be more Variaxes in the future, and I'll definitely buy them. If I hope for something in the update, is some bigger manual, maybe more tutorials, stuff to learn better how to get the best out of your instrument. Also, a feature that self balances volume of strings would be awesome.
I may sound a Line6 fanboy, and I may actually be one, but Variax is the work of geniuses, and in my opinion is underappreciated in a huge way, I really can't get why every guitarist in the world doesn't have one in their guitar rack, if you give yourself the time to learn how to use it, it's really really the best purchase you can do versatility-wise.