Attention Lowther owners DX3 vs. DX4

I have recently inserted a pair of new DX3's into my Lamhorn cabinets and as they breakin I am surprised how much I like them. I was prepared for all the nasties (lowther shout, lack of bass ect) but it has me thinking what the DX4 might bring to the table. My Lamhorns came with AER Mk3's which sound incredible and very smooth and have better bass than DX3's. I love both drivers, the lowthers are more dynamic.

Question what sonically is the difference between the DX3 & DX4's? Thanks in advance for any input.