Von Schweikert VR-4.5 vs. VS VR-4 Gen III HSE

I own a pair of Von Schweikert VR 4.5 speakers. I was wondering if any of you had ever had a chance to compare this speaker to their VR-4 Gen III HSE speakers? I checked the specs and the drivers are different. Not sure what parts they might share. Do you know what year(s) both were manufactured? Did VS produce the Gen III right after the 4.5? If you have heard or owned both, what did you find to be the differences? I'm still stunned at the amount of transparency/soundstage/detail/air (fill in your own words) that I am getting out of these speakers. And I'm still working on getting them dialed in. Yes, everything upstreams matters a lot. Am loving tube amplification on these so far. 85 watts per side seems to be enough for now.