Magneplanar 1.7 vs. older 1.5QRs?

has anyone compared the newer 1.7s with the older 1.5s?
personnaly i think the 1.6 were some of the best,and overall seem to have the most praise from my experience .Placement is key if thats a go they are  all tough to beat imo .with two small subs 8-10"