You really need to have it set up properly before you can make any judgements. I wouldn't knock the mmf. It's a great unit and with the proper cartridge can keep up with the best. Do you have a scale and geo disc or protractor?
I spent many years with the 2215B and it's a great unit for the money. Older receivers have decent phono stages. However, unless you upgrade the receiver (even to a bigger Marantz 2286 or so) you will never hear the full capabilities of the mmf or 1200. You simply don't have enough power at 15 watts for the infinitys. Also, a better receiver of that era will have a better phono stage.
I spent many years with the 2215B and it's a great unit for the money. Older receivers have decent phono stages. However, unless you upgrade the receiver (even to a bigger Marantz 2286 or so) you will never hear the full capabilities of the mmf or 1200. You simply don't have enough power at 15 watts for the infinitys. Also, a better receiver of that era will have a better phono stage.