Horsepower: Blendtec: 3 Vitamix: 2
Watts: Blendtec: 1580 Vitamix: 1380
Blades: Blendtec: 2 prong Vitamix: 4 prong
Weight: Blendtec: 8lbs Vitamix: 13lbs
I have to start by saying that for years I have always been singing praises about my Vitamix. I didn't think that I would find a better product, but then I tried the Blendtec. So, here is my comparison:
Pros: some are sold with a cookbook, comes with a tamper.
Cons: more difficult to clean the bends and curves of the jar, easier to cut yourself of the blades, the long/skinny shape of the jar made it so that sometimes the top of the picture would not blend without using the tamper, my tamper broke, limited colors, too tall to fit under kitchen cabinets (though the G-series is apparently shorter), heavy/clunky, not great customer service*.
*As a side note, when I was having an issue with my Vitamix, they offered me a "loaner program" while they would take up to 4 weeks to fix it. This "loaner program" consisted of me paying for a new one out of pocket and them accepting my return of the new one once my old one was fixed. Doesn't really seem like a "loaner program" to me. The name sounds as if they would send you a "loaner" one for free to use in the meantime, but that really is not the case since you have to pay hundred of dollars upfront. Maybe those types of customer service issues wouldn't bother you, but they make a big difference to me.
Pros: the Blendtec 725 blender keeps track of how many times you have used it and gives you codes for free and discounted Blendtec products at various milestones, easier to clean, sleek/modern design, more color options, lighter, computerized controls, longer/more comprehensive warranty, great customer service.
Cons: Some of the models don't come with a spatula (but you can easily buy them on their site separately).
Though the cost is pretty comparable for both products, you can get certified refurbished Blendtec blenders for a fraction of the price and they still come with a 7 year warranty. Plus, the Blendtec blenders are lighter with more horsepower and wattage. So, in my mind the winner is clear... Go for a Blendtec!