I've rebuilt a 2-group Linea, and I got to keep it to use for 2 months. I love the way LM builds machines; no short cuts, no half-measures. If anything, they over engineered the Linea. If it wasn't so damn big I'd have kept it for my daily machine - first shot, every shot, the same temp all day long!
I haven't seen the inside of a Synesso, and the Linea is the only LM machine I've had my hands in.