The Blendtec has a 3 peak hp motor, blunt blades (which are allegedly maintenance free), a taller profile container, presets and 8 year warranty, but lacks a tamping tool which is a huge selling point for me.
This vitamix has a 2.2 horsepower motor, sharp blades (that may go dull over time) a lower profile container, no presets, 7 year warranty, and comes with a tamping tool.
Having owned both blenders at one time or another I would probably take the blendtec over the vitamix. Though I generally prefer a vitamix, IMO the explorian is not $50 better than this blendtec. If this were a classic series vitamix for the same money, or even $100 more I would have it instead no questions asked.