Yes, but I wish they would offer more features/performance for the price.
I am vastly more productive sitting at my desk with that giant screen, set at a proper level ahead of me than peering into the (admittedly superior) display of a rMBP.
While the rMPB is clearly the OSX machine that Apple focuses on, the imac users are a loyal group who are not looking to convert.
I'm open to fusion drives to keep storage specs competitive to other desktops until SDD's can match capacity, but the display and the GPU need to meet the standards of the rMBP. And all levels of iMac needs to be able to be used as an independent display.
Ability to upgrade RAM would be nice too. Most informed buyers will buy the RAM they need at initial purchase, but I think this limitation on the current machines turns off people who find their needs changing after purchase. It wouldn't bother me if the unit had to grow thicker again to accomplish all of the above.
Unless apple can do the above, I would feel as if I'm severely short changing myself buying a iMac over a 15" rMBP.