Probably very much not useful on simulacrum & many many other spells. Treantmonk had a video that really nailed the problem with spells
Treantmonk is right.
And this certainly does not apply only to spells.
If we wanted the new edition to make fundamental changes to classes and subclasses they should have done the same there. That is, not done a public playtest, and certainly not limit themselves to only changing stuff that gets a massive approval rating.
Like how wonky the six saves feel (even a level 20 character will have naughty word saves that make you feel like a level 1 character), how the unnecessary split between when subclasses start make it impossible to mix and match subclasses between classes, how high level play suffers from there only being one subclass choice and not two, and so on and so on...
By offering the playtest and binding themselves to its results, they have all but assured themselves that they can blame 5.5 not really fixing much on "that's what y'all wanted".
In the end the edition will have changed a myriad small details. This will not actually meaningfully improve the fundamentals of D&D 5. But it will certainly make it pleasingly (for WotC, that is) hard to stick with the 2014 edition.
Remember: the primary goal here wasn't to fix D&D. It was to rejuvenate sales.
That some player will be happy their barbarian can dish out 3 more damage, or whatever, is not evidence to the contrary.
In other words, very much like the approach taken with 3.5.
And more to the point, very unlike the approach taken in the years leading up to the 2014 release of 5E. An edition that really, truly,
fundamentally improved the game of D&D.