...Very late to this party.
I have been trying to find reviews on the 45 rpm LZ's because I have just heard one disc of the LZ IV album (battle forever more & stairway to heaven) I have NEVER heard it sound so good, and it does sound great, weather your comparing it to modern recordings or older ones.
As a point of reference, I have many UK 1st/early pressings and US WLPromos, all in Near Mint condition, I use a older Forsell linear tracking table with a $3,000 sumiko cartridge, Technical Brain solid state electronics, and highly modified Silverline Grandeur speakers.
Compared to my two minty UK red & plum label pressings of IV...the 45 rpm is noticeably better from top to bottom.