I bought 2 Stearn''s auto inflatables with the integral harness. We liked their design, but only chose them over their competitors because my buddy works for an outfit that got the Stearn''s products at wholesale.
Using Jack''s advice, we did a wet run (can''t call it a dry run, can you?) in the pool and it has incredible buoyancy, at the price of mild discomfort. The re-arming process isn''t too difficult, and in the deflated mode, they are much more comfortable than the standard Type II or III. Frankly, they all seem to ride high up on the torso (a necessary thing) which isn''t comfortable to me.
Good luck on your choice.