Definitely try them out to see which one you like the best. Sometimes when piecing it's nice to be able to change the needle position slightly in order to get the perfect seam width. If the Allegro doesn't allow you to adjust the needle position, that would be a negative in my book. Also check to see if the Allegro allows you to choose either needle up or down when stitching. If you want to FMQ having needle down makes it a little easier as you don't have to reach for the hand wheel with one hand in order to put the needle down before changing your hand position.
Rob