I also sailed on the Edge in its early inaugural days. And to the OP, I've also sailed on Allure and Grandeur that you mentioned, plus other RC ships and even more Celebrity ships going all the way back to the Zenith days.
As far as the Edge is concerned, it is really a personal preference and depends on how you cruise.
For me, I do not like the Infinite Verandas, which I was in, and would not sail in one again unless it was in a cold weather itinerary (think Alaska or Baltics) where I would not use a balcony anyway. I much prefer a regular balcony as I love to spend time out there. If you are a person than doesn't really care about the balcony, the extra cabin space of the IV would serve you well.
I really missed the Sky Lounge, and the other bars/lounges that the M & S Class Celebrity ships offer, and even the variety of other lounges that RC and other cruise lines offer. I do feel that if you are booked in a suite on the Edge class you will experience a totally different cruise than someone not in a suite since you have access to other areas. The Martini Bar just doesn't cut it IMO as it gets way too crowded, and I did find the seating in the Eden Lounge to be uncomfortable for the most part, and The Club Lounge atmosphere was not to my likely as well.
I loved, loved the 4 MDR concept! And the theatre design in the round was great as well.
I know, Celebrity has tweaked things since I was on the ship, thankfully. And, because of that, I have actually booked the APEX with some friends for Dec 2020, but in a Sunset Balcony. Willing to give it another try, but at least I will have a REAL balcony! We will see what happens The Second Time Around.