Of the 8 leverguns I own, my two Rossi 357mag levers, a blued 20" rd bbl carbine and a blued, case hardened 24" oct bbl rifle are my favorites. The 357mag caliber is a blast to shoot, and if you handload, it's cheaper to shoot than the cheapest 22mag ammo. While I have a little Henry 22lr carbine, I agree that the Henry Big Boy in 357mag is a non-starter due to it's lack of a side loading gate and it's significantly heavier weight. While I have 2 Uberti levers in 45 Colt, a 19", 1866 Yellowboy carbine and a 24" case hardened, oct bbl rifle, their shared togglelink actions limit the usefulness as they should be limited to std pressure (14,000psi max) loads; what the action was designed for.
While the 16" trappers are currently popular, I'm not a fan of their balance and you loose the benefit of the extra barrel length for both velocity and sight radius. While the 20" carbine is a joy to carry in the field and the best all around choice if you only have one, I also like the extra velocity produced in my 24" rifle. Further, with a tang sight, you've got a 30" sight radius that really helps shooting longer ranges, something you'd not think a pistol bullet would do well.
However, the 357mag caliber is great in a levergun, especially when loaded with 158 or 180grn bullets at full power with magnum powders like H110, 296, or Lil'Gun. The extra barrel length allows the powder to develop the max velocity. I use my Rossi rifle with it's tang and globe sights to shoot steel plates at 300yds. From mouse fart light loaded 90grn to fire breathing 158grn Buffalo Bore 357mag Heavy ammo that they claim produces 2,153fps in an 18" bbl Marlin, it's a versatile caliber.