ZellSF: That's really just a variant of BG1Tutu/EE. Same considerations apply.
Think about what you wrote for a moment. Why would there be a Trilogy version for EE (EET) if what you say was true? The considerations you wrote (basically change of rules and UI) apply, of course. But there are more, and they are not minor:
Leveling - there are no "per-chapter" or other partial caps but only one cap from Candlekeep to the Pocket Plane and beyond. It even has been addressed by tweak mods, nerfing the XP rewards in different situations.
Continuity - Experience and stats of the PC and NPCs are transitioned into the BG2 portion. And adding other mods, you can even decide what happens with all the NPCs and the equipment present at the end of the BG1/TotSC portion of the game (differing from the canon story line if you wish so).
Updated - BGT/EET are being worked on to this day, while BG1Tutu/EasyTutu, as problem-free as they may be, have not been worked on for (I believe) 5 years or more.
Mods - All mods installed that apply to the mechanics, enemies and equipment will apply to the BG1 portion as well, even if no equivalent standalone mod exists for the original BG1. Most of those are, of course, also available for Tutu (or at least EasyTutu), but you must decide if you are willing to endure the changes in both portions of the game before installing one.
And last, but not least, for the ones that own the original games, the most complete way of installing mods and mega-mods, ensuring their inter-compatibility, is the Big World Project install order, which uses BGT. Meanwhile, I would not risk installing Tutu with more than the 2 or 3 mayor tweak and fix mods, at best.