Bought the Blendtec when Vitamix #1 needed service. I found the Blendtec was noisier and didn't like that it didn't have a tamper. Also I like the dial-type speed control on the Vitamix. MrDaBaDe disliked the Blendtec so much that he went and bought a second Vitamix immediately after trying the Blendtec so that we wouldn't have to wait for the Vitamix to come back from being serviced. We gave the Blendtec away. I have both the shorter, fatter (under-counter) model and the original taller type. It feels like the taller one is a little faster at getting things to the consistency that I want, but both work, and I've never done a real timed test using the same ingredients to be sure, so it might just be my perception.

We also have a Vitamix immersion blender that I love, and I can say from experience that the Vitamix immersion blender is much better than the old Braun we used to have. That said, the immersion blender is not nearly as versatile as the traditional one--it's just more convenient for a few tasks. So if you're only going to buy one, I'd go with the traditional one.

My only caution on the Vitamix is that if you use it to grind wheat it will dull the blades, and the flour created is not as good as what you would get from a dedicated mill. This is probably true of the Blendtec as well, but idk because I haven't tried it. If you want to mill flour, I like the Whisper Mill/Wonder Mill best of the ones I have tried.