Ok, shifting options. I test drove an
M5140 before I got my
M6040. There wasn't much difference from what I recall except the 6040 has a larger engine. I don't know what options exist on the other models being discussed, as I haven't driven them.
The
M5140 should be sychronized in all 4 gears of the main transmission. Meaning you shift it like a manual transmission in a pickup, depress clutch and shift on the go, up or down. You will still have to stop when changing the Hi-Lo range, but not between the 4 gears in the main transmission.
Non synchro means you have to depress the clutch and come to a stop to shift some of the gears in the main transmission. I wouldn't want that personally, but people get along fine with them.
Next is the shuttle, which is a lever on the steering column to select forward or reverse. You can get Hydraulic shuttle, or you can get Synchro shuttle.
Hydraulic shuttle has a wet clutch. You don't have to clutch or even come to a full stop when going from forward to reverse. Just move the lever. Kind of like a backhoe if you've ever run one of those.
The Synchro shuttle has a dry clutch. You have to depress the clutch and stop to switch from forward to reverse. I personally thought the hydraulic shuttle was worth the added cost, but not everyone does. If you're using the loader much its definitely worth it, IMO.
I think the
M5140 would serve you well. I really like my
M6040, and there's not much difference there. I run a LandPride RCF 2772 which should be similar to your Bushhog, and my tractor hardly knows it's back there.
Good luck with your decision.