pro star

Pretty much agree w/ everything EZ said. Lots of room. Especially if you have the Hi Rise. Since Boyd runs mainly FB's my guess is they're not.

Quirks - No true Jake. You learn to make it run at higher rpms to have it work effectively.

Factory coax is junk.

A/C on these is hit or miss. There are several topics in the forum regarding this.

Blackout covers for the window sleepers. Reinforce the outer seams with additional velcro.



I liked the fact I never have to screw around with DEF at the pump.

Mine has the ISX 435. Pulls pretty darn good, with no significant problems. Nice ride.

 

Agree with that.....The AC had some issues on mine but they updated some software,replaced a sensor and it will freeze you out.
The Jake on mine will about put you through the windshield when empty or bobtail.....
The no DEF fluid is good.....It uses fuel to burn out the DPF filter.

 

The Cummins ISX has the best engine brake there is on the other hand the Navistar Maxforce has a useless engine brake. It seems like all brands have issues with emissions equipment (thanks tree huggers). Seems like quality has gone down with all brands. The 660 is not as well built as your 600. Good luck whatever you do.