Bear in mind that the 5LS (what you're calling the Ref 5) uses the same mids and tweeters as the older Ref 3/3.0/3.1 speakers, plus a bunch of 4" "woofers" pointing to the rear. I heard the 5LS speakers a couple years ago when I was using Ref 3s with the dedicated Mapleshade stands and was not sufficiently impressed to consider upgrading from mine, although the 5LS certainly LOOK impressive.
When a friend brought over a pair of Gallo Stradas, which use Gallo's latest generation mids and highs, I was able to compare them to my Ref 3s and the Stradas were CLEARLY superior, leading me to buy a pair plus a pair of TR-3 subwoofers. The Stradas and TR-3s use the same drivers as the $6K (MSRP) Gallo Ref 3.5. I seriously doubt that the 5LS would sound better than the 3.5, but I have not heard them side by side.