This thread helps to confirm two things that I have been saying for awhile;
1. First the 2013 Mac Pro is a terrific computer but for a limited number of uses. There is a lot of flexibility and technology left out but for the intended users that is not only not a problem but actually an asset.
2. Apple's product line is riddled with holes like Swiss Cheese. Apple is leaving a tremendous amount of money on the table by not producing a more powerful, user configurable mini (a midi?) and a mini-tower with PCIe slots, space for a couple of hard drives, space for at least a thinline ODD, four accessible RAM slots and choice of top i7 processors.
Then again how much of a market share does Mac have to grab before they get into Microsoft-like trouble?
Have you read the isaacson Steve jobs bio? Apple already has a wide palette of computers that is on the edge of what's good for them I'd say.
First thing Steve did when he came back in 2000 was cut the whole sortiment, get rid of useless models and FOCUS on a few great products!