The price difference is now +$850 for the 5.0 ($4,350 vs $3,500). When I bought a 4.0 it was on sale for ~$2,500 and at that time the 5.0 was $5,150, more than 2x the price of the 4.0. We then also got a 5.0 step thru for my wife when the price dropped to $4,350. Owning both, I can definitely...