Vandersteen 2ce Signature vs Tekton Double Impact

Those are both wonderful speakers.  They are kind of at the sweet spot for most people in speakers where you will get the most return from your purchase.
Which one that is better for you depends on what sound you like in your music. So I would highly suggest for you to listen to them before you get one, or get them with a return policy and be willing to pay for freight.
If you like the vandy's better a couple more speakers you may really like also are the vienna accoustics mozart grand, sonas faber venere 3.0. If you like the tektons better you my also like some thiel 2.4's especially if you like planers.

Eminent Technology LFT-8b, $2499/pr.

I’ve owned a lot of speakers over the years including Vandersteen, Magnepan, Von Schweikert, Harbeth and others. You’re right, Tekton doesn’t use the most expensive drivers or elaborate cabinet design. But, the tweeter array Eric has developed and how he has implemented it in a variety of speakers is the REAL DEAL. I don’t think you would be disappointed.

For anyone interested in the physics of multiple tweeter design, watch GR Research's Danny Richie's Tech Talk Tuesday videos on You Tube, a couple of which deal with that very topic.

@OP,
I wanted to inquire before giving an opinion. Since you are familiar with the Vandy 'sound', then that makes it easier to give advice.
I know this is probably going to start a flame war, but I will give my opinion nonetheless.
As previous posters have indicated Vandersteen has been around for decades. For good reason, they provide great sound at a reasonable price point. Add to that time and phase coherency, in the higher models- pistonic drivers and  equalized bass.
I have limited experience with Tekton, but I and a few others found them to be engaging at first, but eventually fatiguing as the listening session extended. -Which is something a Vandy speaker never does.
I believe Tekton offers a trial period, so you can give them a try and only lose shipping if you don't like them. Though from what I have read, you have to send them back in pristine condition.
For my money, I would get a pair of used Treo's (Quatro's if you can swing it). Don't sweat the CT tweeters. Otherwise, a pair of Magnepans or Sound Labs if you want to try electrostatic speakers.