Re: radial arm saw????
It really depends on the age and quality of your saw. My Craftsman Industrial RAS is actually made by the original DeWalt (so were the Montgomery Wards PowerCraft saws). A good RAS will outperform all portable miter saws, just as a cabinet tablesaw will outperform a benchtop saw.
However, a poor quality RAS will actually produce lesser results than a good quality miter saw.