If you buy a cutter that has a slip clutch!
As soon as you get it home, loosen the slip clutch, be sure it spins free, then re-tighten the clutch per manufacturers specifications.
The slip clutch must work properly, otherwise if you hit something solid, if the slip clutch does not slip, you could bust transmission gears.
Just a heads up.
Sometimes slip clutches have paint on them that keep the clutch from working properly.
Also, if you buy a cutter with a shear pin, be sure you have soft shear bolts, not hard bolts.
I have a 5 ft and it works fine.