I had a 2007 1540 with a FEL and Powershuttle. It was a *fantastic* tractor. Easily the quietest tractor I'd ever owned or seen, it started instantly even in very cold weather, and was well-made from end-to-end. Unfortunately, I ended up having to sell it in 2009 after the economy tanked and my construction company lost 70% of its business.
In 2013, I bought another MF, this time a 1643 Hydro with a FEL, and while it is overall an improved tractor vs. the previous one, the 1540 was quieter, had better fuel economy, started a little better, and I liked the floor mounted loader joystick better than the fender mounted one on the 1600 series.
Selling the 1540 was difficult because it was the finest tractor I had ever used (I grew up on a farm that my parents still own) up to that point and obviously if I hadn't sold it, I never would have purchased the (slightly improved) 1643.