Break it down. 1 is 2k & the other is 4k. Both are 60hz. Mostly used for work & browsing. Both are 27". The 2k is 350nits & the 4k is nice & bright as well. (Not sure if the listed max SDR brightness of 329 is the correct score but typical is 300nits.) The 4k was noted to have brief image retention after a static scene is shown which isn't good. Can't find the same info for the 2k. The 4k has a noted 9+ms input lag which reading for this monitor is low. The 2k's input lag is 4ms Grey-to-grey. The 4k is $350, the 2k is $250 (depending on location, price will change)
Both are nice, I'd go for the 2k myself. I spent a long time looking at 2k & 4k monitors before settling on my MSI Optic 32" 2k @ 144hz. However, I'm sure a monitor guru will be along shortly and will weigh in with their thoughts. The above is just my own opinion.
Might be worth noting: In-store at a local BestBuy, I had a TV Tech/salesman tell me that while having 4k for some work purposes was nice, was still pretty much a gimic in sizes under 40"