It's hard to judge these album outside of their time frame.
Right now, I'm loving The Mountain every bit as much as I enjoyed IAW when it came out. I'm completely in love with every single note. I really like Visions and Aquarius, and they are growing on me every day....but I honestly believe that when the smoke settles, The Mountain may be in my top 2 or 3 albums of all time.
We'll see. The albums that hit me the hardest out of the gate, sometimes don't have quite the staying power. For example, my first exposure to Pain of Salvation was The Perfect Element. That album hit me SO HARD, and to this day I love every single note, and I think it is a near perfect album. Remedy Lane OTOH did not grab me at first...and after five spins, it gathered dust on my shelf for 6 months. But then I heard my stepson listening to it, and it hit me. Now, the lyrical content of Remedy Lane has pushed it above TPE in my eyes...but only just barely. And this being in spite of the fact that TPE has no skip tracks and RL has one (Waking Every God).
But that's just the reason why I think The Mountain will be different. The lyrical content is so much more personal to me. It has the very personally moving lyrical scale of a "Remedy Lane"...but with the musical perfection of Images and Words. Heck...it may become my all time #1....but only time will tell.