I think the iMac Pro is a triage and the Mac Pro will carry similar (albeit updated) components, just in a more modular design; The iMac Pro isn't even coming out until 2018. Also, Phil Schiler said this on April 4th of this year: "With regards to the Mac Pro, we are in the process of what we call “completely rethinking the Mac Pro”. We’re working on it. We have a team working hard on it right now, and we want to architect it so that we can keep it fresh with regular improvements, and we’re committed to making it our highest-end, high-throughput desktop system, designed for our demanding pro customers." With the triaged iMac Pro coming out in "2018", I highly doubt we'll see a "completely rethought" model anytime in 2018, possibly into the first half of 2019. In the meantime you're looking at a current non-modular, heat limited mac Pro with meager components in relation to what you're paying. If you're really willing to stick it out that long, more power to you. Personally I moved on from a 4k iMac to building out my own custom windows box and while windows isn't macOS it does have amazing hardware support and (arguably just as important) better OS level implementation of GPU accelerated drivers. Mix in the AMDs newly released Ryzen multi-core chips, and upcoming "Threadripper" architecture and you're looking at being able to build a monster moGraph machine for a fraction of the cost of the current mac pro, upcoming iMac Pro (which only supports OpenCL related GPU acceleration), and definitely the future modular New Mac Pro (whenever that comes out). Making good work is more important to me than loyalty to the OS. Yes MacOS is much more seamless, but I don't think the juice is worth the squeeze anymore.