I never recommend a lunch box for a rear axle. These units, unlike a Detroit, actually wear over time. The lack of a hold out ring assembly means the edges of the teeth wear with every engage/disengage. If you MUST run one of these in the rear axle, swap the unit around, side for side, every couple of years. CS is right, failures are common as the tiny parts tend to break.
Generally, the larger the Detroit the smoother it is. The internal lash of a Detroit is one of the things that can make them rough. A 44 has less lash than a 35 and a 60 has less lash than a 44. The 35 is also a c-clip model so no 'Sof-Locker' feature is available. A 'Sof-locker' version is much smoother. Nearly all non-clip models since about the mid 90's are Sof-Lockers. Automatics drive better with a Detroit than manual and a longer wheelbase is smoother than shorter.
A spool can kill your turning radius. While you might not notice it on a snotty trail, on a dry woods trail it is very noticeable. As a DD it also adds a ton of stress on your axle shafts. They get a lot more torsional twist until the tire loses traction and spins on corners. Depending on the use, axle shaft failure can be more frequent.