I've toyed with the idea of a semi fat, Hard tail with a fat rear, Still pondering if the concept would actually work the way I would want it to.
"some" rear suspension down hill and grip uphill without the weight, maintenance or cost of full suspension.

The 29er hardtail I have now is a great bike, but it's not the bike for me, I bought it as a learning curve bike and are pondering options for the next bike.