Like I said the main point of it is to increase the displacement by going way over on the bore. increasing a piston bore is a way to gain back some bore stroke ratio for rpms when stroking a motor, or to push it over square to increase the rpm stability of the engine, increased displacement without increasing piston speed. The iron liners have the side benefit of being more stable and more durable as well as not having to throw the block out of a piston eats itself. These are really only gains for serious competition use like I said earlier in the thread if you are DD'ing the car a sleeved block isn't for you.
I could agree that you aren't making the "block" as I assume you are referring to the original aluminum, any stronger, but by increasing the cylinder strength without too detrimentally affecting the the strength of the mains area, and increasing the cylinder stability and strength which increases ring seal and reduces piston to wall friction, you are making the overall assembly "stronger" in that it is better suited to making more power than it was before. Sleeved motors can be bitch to maintain considering the usually associated sealing issues, thats why they are only for those with the money, time, and need to squeeze as much power out of the motor as is possible, and .3 extra liters from running larger pistons goes a long way towards that especially once you begin to boost the engine.
Edit: as for the omega not the first place I heard it but here
Read post 3 from AMS
Also what happened to your wet sleeve engine did it crack in half on you or are you just having gasket issues?
Also this a fun technical debate isn't it? I wonder how many people are actually following it.