Hey Rachmaninoff_forever...
Damn, I did play that - a while back in 2010. I don't buy into the whole 'if you can't sight-read it' nonsense either. No one can sight-read things like Petrouchka or Brahms Paganini Variations, or Balakirev's 'Islamey'. Not even Liszt probably would have been able to do that.
Main thing is the stamina. Learning the notes in principal... is easy. Slowly getting it up to tempo is a righteous pain in the arse (mainly the 1st and 3rd movements). I also however had the problem of trying to relax as I played. I as brought up for almost a decade being taught by amateur piano teachers who didn't give a stuff about my posture, hand control, phrasing, articulation or anything like that. Most of the time, it was - if the notes are right, you're doing great.
Trying not to get tense as you build up the tempo is a tough one. The other sucky thing was I had an edition without fingering... NO fingering at all, and although I managed to come up with a good fingering for my hands, it was time consuming.
Last was time. Having the time to really sink into a piece like this is the main thing. When I was unemployed in 2009, I was still living with my parents, so I spent 7 - 8 hours a day practicing, while I was slowly trying to accrue employment. I also spent over a year trying to practice this piece on a decrepit 25 year old beaten up Upright Piano. It was one of the cheaper model Yamaha's that had endured my LMusA pieces, as well as my university repertoire. At the time it had to do until I could save up for a decent piano.
Playing the piece on a Grand Piano however (or I suppose a new, well maintained upright) was key however to really getting the most out of the practice.
Hope that helps as a start. If you have any specific advice - I'm always happy to help.
Best of luck. I remember when my piano teacher suggested I play it, and I had a printed copy of the score in front of me. Seeing Weissenberg playing however almost scared me... It was harder than anything I had ever seen at that stage for the solo piano.
PS. Most people can't use that argument that
'if you have to ask the question then it's too hard for you'. Unless you have perfect pitch and can instantly visualise the music on the piano keys, you can't just tell how hard a piece of music is simply by looking. Yes there are techniques we may haven't seen before, but you can't really imagine the end result from looking at sheet music.
Topic: Hey Perfect_Pitch I have a question for you