Just stay away from the Atom processors. They are used extensively in the cheaper units and are under powered. I have had everything from Atom to i7 and wouldn't go below i3, preferably at least i5.

It is like maintaining head room in music; you may not need it everyday now, but you may want the extra later on.
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pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact