The props listed in the tech notes and manuals are just guidelines. The manufacturers will never be able to test every possible combination. You can use any prop that runs well without overheating and flies the plane the way "you" like.

You could switch to a 10x5, three blade such as http://masterairscrew.com/new10x53-b...propeller.aspx
The engine will likely turn several hundred rpm more than with the 11x6 but top speed "should" go down by about 9 mph.

If landing speed is the issue, I do not believe the prop is the problem. At 2500 rpm, a 6 pitch prop would only want to go 14 mph under laboratory conditions so I think the others are right that the plane is coming in 'nose down' and gaining speed because of that.