According to the updates for the 2018 MBPs, I'd suggest you wait.
Surely, no one could assure there will be a refresh for iMacs this year, but it's worthy to wait for if you don't have an immediate need.
The 8-gen CPUs are much more powerful than the current models. Even if you don't need that much power, you could get a better resale price once you want to change your Mac.
Rumors have it that there might be some releases from this Augst to October, is only 2 months or so.
If you could wait, should wait a little bit more.
Surely, no one could assure there will be a refresh for iMacs this year, but it's worthy to wait for if you don't have an immediate need.
The 8-gen CPUs are much more powerful than the current models. Even if you don't need that much power, you could get a better resale price once you want to change your Mac.
Rumors have it that there might be some releases from this Augst to October, is only 2 months or so.
If you could wait, should wait a little bit more.