Shoulders are probably the only thing I would let a smith machine slide for.
They recieve sooo much stabilization in everything else. Chest, back, arm work -- so I doubt stabilizer will be underdeveloped.
For me the ROM a smith provides feels natural and quite good, but if your genetic structure doesn't agree with it, then I would stay away.
Anyways, here is my current routine.
Db Shoulder press
3 x 8, 6, 6-4
Db Lateral
3 x 10-15ish
Smith (or hammer strength) shoulder press
3 x 8-12
Cable Laterals
3 x 10
*Note: I train rear delts and traps with back.