If by 'characteristics of a 7x7' you mean shape... I'm really looking forward to any changes to the core material. One of the rounded center pieces of my 6x6 broke off and I don't solve as much as Dan or Erik, nor did I force turns as it was unmodded and I knew how much it pops.
7 hours to do the first three mods. Then I did the fourth one two days later and it took me way too long and I failed few times, superglue went to the screw and the pins fell off. Fortunately, I was able to fix those and now it's perfect.