I've got to go along with the group. The VK is now the 4th model that I've added to my stock. I also have an ample supply of 401, 510 and JS hardware. My initial impression is that the VK beats the 401 hands down. Just as much flavor and throat hit with longer lasting batteries. I'm not going to compare it to the 510. I really don't get the attraction to the 510's I find their performance poor. You always seem to need to 'fiddle' with it or change batteries or top it off or something. Even when working properly I find taste and throat hit to be mild to none.
My favorite is the JS with an 801 atty. Consistent performance and long lasting.
Back to the VK... this one is a 'gotta-have' and, for many I'm sure, will be their favorite. The carts are genius and can easily be refilled [not sure how many times as I've not had it long enough yet] The battery charging case is far superior to the one I have for my 510. The performance in terms of vapor and throat hit are immediate and consistent [and this is with 0 nic juice].
Steve seems to be a guy that you can easily trust. One of my two batteries had a minor defect and he responded to my email within minutes with an offer to replace it, no questions asked. The stuff arrives on the west coast in a matter of a couple of days and everything is well packed and presented.
The juices are a matter of taste and he certainly has a wide variety. Of those I've tried I prefer the Camel, tastes spot on to an analog. The pineapple was pretty nasty, kind of like vaping perfume.
I'm not sure if the VK is available from anyone other than Steve but, if you don't already have one, go get it and, get it from V4L.
You gotta get some extra bonus, even when ya get the discount as well
