I don't hate it. I still think it's cute and cool. But they all but destroyed it's personality. I like the idea of a super-powerful Pikachu, as stated before, but there just isn't a sound enough explanation.
But, I think this actually gives potential. Like I said earlier, if they made a movie or special that gave some sort of awesome explanation, that'd be cool.
Like, perhaps Uberchu is actually another, as-of-yet unknown legendary that somehow lost it's memory, most of its power, and was transformed into a Pikachu. Or perhaps Uberchu bears some sort of connection to a legendary, or even Arceus.
You have to admit, a movie or special about this would be pretty good, and would clear up a lot of issues with the anime. Plus, it would make all the fans realize that Ash's Pikachu really is special.