brakes decision - avid or shimano

M6TTF

got a new bike coming in a week or so - it's got XT disc brakes fitted which I'm led to believe are very good? However i'm a big fan of the elixirs fitted to my other bike and am considering selling off the XT's as soon as I get it to buy some elixirs... My thought being that having the same brakes on both bikes will good for familiarity.

How do they compare? - should I give the XT's a chance ? If I keep them does it mean another bleed kit to purchase?