Morkus from Orkus
No. I'm not going to slog through all the threads and pages looking for the posters who have been telling me that it will be fine playing the two versions of the game simultaneously, because the new classes will be balanced with the old ones so one edition's classes won't be more powerful than the others. I'm certain that @Parmandur was one of them, but there have been several.Do you have a citation on "... Will my roughly equal"? They have said they will be compatible, but they explicitly stated they are fixing broken elements (twin spell) and powering up weak ones. They have never claimed a 14 Sorc and a 24 Sorc will be equal, only that if you prefer the 14 Sorc you could still use them, 15 spells and all.
If they aren't balanced, though, then WotC is wrong about backwards compatibility. As I pointed out to someone else, I COULD use the 3.5 version of wish in a 2014 or 2024 game. It's not going to cause the game to melt down and stop if I do that and the rules are similar enough to be workable. Unbalanced, but workable.