27min is very respectable.
I was desperate for an upgrade this year as I was on a i7 3930k + ASUS Rampage IV Extreme since 2012. This was a very good workhorse, but over the past year I found myself modding BIOS just to get basic stuff working like booting from NVMe add-on card. I wanted to stick with Intel but was disappointed with them over the past few years so I went with AMD this time around even though they did disappoint me in the Bulldozer era but I could not ignore the reviews.
Just around the time when Chia went mainnet I was able to obtain a 5950X + ASUS X570 ROG Crosshair VIII Dark Hero at my “local” Microcenter and was blown away by the performance. I started plotting on a Samsung Evo 970 Plus but was concerned that it will not last too long so got some PNY CS3030 (before they silently changed the TBW) and used them in bifurcation via an add-on card since this MB supports it. This was ok but as soon as MadMax came out I maxed out the RAM and seen it spit out plots at ~26min in Win 10. Then I found out that Linux performed much better with MadMax so I installed PopOS in dual boot and on Linux I’m still doing ~21min a 32K plot. Since then MadMax added support for 33K & 34K and it has a much better performance with these as well compared to original plotter and you can see my stats for these at the post below. All in all I’me very happy with may upgrade and the fact that I was able to reuse by older GPU saved me and kept this upgrade <2k 
I considered Threadripper but did not want a space heater warming up my room and did not have the need for all of the PCIe lanes, plus it was cost prohibitive for my needs. From what I’ve seen from other posts TR does not do much better with MadMax then my current CPU so I think I made a good decision.