As Oblivion stated, just do a creative google search about Kiesel issues and use your best judgement.
I can't speak for the Vader model, but I had an absolute horrible experience with a new Aries 6 Kiesel build a while back. From a play-ability standpoint, the guitar was utter shit, and the customer service at every level of the company was the worst I've experienced in my 42 years. After a bit of a fight with them, they took it back and refunded me.
I'd never buy another one of their products and don't recommend them at all. For the record, I was a pretty big Carvin fanboy, still love my ST300c, but Kiesel.....Never Again!
Too many other companies out there offering beautiful instruments for similar prices but that build a guitar correctly & aren't shady as fuck.
That was my experience however, and there are many here and on other forums that have had great experiences. Do the research before taking the plunge.