Shelter 201 cartridge versus Ortofon 2M Blue

I am considering the new Rega P-2 turntable. I need to use a moving magnet cartridge with at least a 5.0mv output. Both the Shelter 201 and the new Ortofon 2M Blue are 5.0mv. Has anyone either compared or owned one of these cartridges, especially the Ortofon??? The less expensive Ortofon 2M Red got a good review in TAS this year,(I am assuming the 2M Blue at $199 is better).... I am limited to using only a highout MM because of the phono board installed in my Creek SE5350 integrated amp. The Creek uses a passive pre-amp which has no line level and so the volume begins to gain at 1 o'clock setting. Both the Dynavector 10X5 or Sumiko Blue Point #2 are only 2.5mv and would provide only marginally loud volume. Had I know this, I would have bought a more flexible step-up device, but the Creek was cheap and has good specs. All opinion and advice welcomed