Ok, first two things :
1. My Delta's are modded with tape over the back vents and a very small hole poked in them with a needle.
2. I've only got a couple of hours on the LZ A2's so far.
To begin with these two are more similar than I expected but there's still obvious differences.
The Delta's has slightly better soundstage width while the A2's has better depth.
The overall presentation on the modded Delta's are quite airy while the A2's are more intimate and fuller sounding.
Vocals are more forward on the A2's. Despite of this female vocals comes across as very similar on the two, maybe with s slight advantage to the Delta's, while the fuller signature on the A2's gives male voices more weight and a better texture.
Subbass impact and depth is pretty similar but the A2's has more controlled bass. Mid-bass impact and presence is also very similar but the A2's bass is tighter and faster.
The treble presentation is very similar on them.
Take it for what it is: quick and dirty initial impressions