Well I don't have a Vader, I have an Osiris 5 string which is a bolt on headless with a different body shape. I went with the Osiris because I prefer a bolt on and I like a bigger body. Otherwise, they are essentially the same thing. I took delivery in September.
Quick history on me....I'm a sucker for boutique basses. I've been through all the 'store bought' stuff, event he higher end stuff (heck, note my user name!) and none of it does it for me. Point being, I've had nothing but high end basses since the 90's so I have a nice portfolio to directly compare. In addition to my Keisel, I also have three Roscoes, a Warwick Streamer, a Carvin Bunny 4, and two USA Spectors. I've owned and sold more basses than I care to count! I actually wanted a headless Roscoe Century, but at 2 times the cost of a Kiesel, it's just not possible right now.
Straight to the point here, keeping in mind the other basses that I own....I was completely shocked at how much I love this Kiesel. I honestly did not expect it to be THIS good. I've had various Carvins over the years so I know what they are all about and had an idea what to expect. The biggest shocker to me was how much they have improved the electronics. The pickups and preamp are phenomenal. I opted for the split coil P bass pickup in the neck, and single coil soapbar in the bridge. I fully expected to replace the electronics at some point as I have done on every Carvin I've had, but there is no point now. Their new electronics are top notch.
I've had various headless Steinbergers over the years (around 6 of them) so again, I kind of knew what to expect with headless. If you've never had headless, it can be strange at first. You don't have to put fourth ANY effort holding the neck up anymore. It literally sticks up in the air right where you need it. It's a bit strange having the weight of the instrument actually all on the bridge side and it just naturally sits in a playing position without having to touch anything. In all, mine weighs 8.5 pounds. I went with the ash body and 5 piece maple/mahogany neck. I think it can get lighter with different woods, and a Vader will probably be lighter anyway.
Keep in mind that Kiesel is having a price increase on Jan 1st, so order now. I also feel strongly that a multi laminate neck is 100% worth the price. You can get a 3 piece neck for like $180 extra. That's the only upgrade I feel that HAS to be done.
I need better pics, but here is mine.