Yes it does matter, you are offering advise on aircraft you have never flown on a REMOTE CONTROL site. The OP was asking a question directly related to models. A question that not only requires some flying experience but designing as well. The bottom line in answer to his question is that on a typical sport/trainer airplane there can be up to 10 degrees of dihedral without any real adverse affect on the ailerons. However there can be adverse affects in other areas such as control cross couple. Remember that a model airplane is a bunch of compromises, what can be benificial in one area can be detrimental in another. Knowing the desired capabilities before making changes or implementing design features is usually nessesary.