I'd wait until after WWDC just in case, but I see the current iMac line as in sort of a sweet spot. Finally plenty of graphics power to drive all of those pixels, 4 cores is plenty for my productivity, super fast ssd speeds, USB 3 & Thunderbolt 3 connectivity. I see the next few upgrades as being incremental, and maybe not all that soon. And they're old enough to be in the refurb store for your 15% discount!