At HB, we're currently reviewing both machines, but not together.
But I do have a rather odd word of advice. In my experience, there is no systematic taste difference making straight espresso shots on competent machines. There are systematic differences in what kinds of coffees certain machines can make. With very light roasts, levers or double boiler machines with programmable preinfusion fare better than HX machines, since they can make the finer ground, extended shots require to fully extract these. Based on this, you will find no systematic taste difference between the two machines, which can do all coffees with equal aplomb.
There is a huge ergonomic difference between them. On the the DE1, shots are preprogrammed; on the Bianca, they are made on the fly. There's a review entry on this
. As an upshot to this on the fly capacity, the Bianca is more forgiving (if the shot starts channeling, you can slow down the flow and let the puck repair itself). If you are attracted to levers, buy the Bianca; if you want a self restocking fridge with a touch panel, buy the DE1.
If you are truly obsessed with getting the best shot possible; buy neither. You'll end up with the most expensive grinder and machine no matter how you start.