The SBE is far better in the terms of quality over the 11-87. Not only is the SBE a ton lighter it also balances better for me with more weight towards the stock. The 11-87 has a barrel heavy balance for me. The SBE has more features like shims to adjust the stock and an automatic magazine cutoff. The SBE is easier to clean and stays cleaner a lot longer than the 11-87. I'll assume you are talking about the 3 1/2" 11-87. In this case neither will cycle lighter loads very well. None of the five or six SBE's that I know will cycle 1oz loads reliably. Not a big deal as a 3 1/2" model is geared for waterfowling where bigger loads are used.
The Inertia design is simple and clever but, has its uniuque flaws as well. The fact that the the US milatary uses a gas operated Benelli should tell you something.
You're more than likely to come across a Benelli M1/M2 or Montefeltro (both in 12 and 20 gauge) in Argentina than a SBE for doves. The Beretta AL391 is pretty popular down there as well.

Other good choices for a waterfowl shotgun besides the SBE's would include the Beretta Xtrema's, Browning Gold 3 1/2" and Silver 3 1/2", Franchi 912, and Winchester SX2 3 1/2". I like the SBE so much, I almost bought one but opted for a Gold 3 1/2" instead. There is also a SBE and SX2 3 1/2" owned in my group of buddies as well.