Saw the Double Rainboom livestream. I have mixed feelings about it but user http://intensedebate.com/people/NostalgiaShmltz over at EQD took the words right out of my mouth as his opinion is
dead on the same as mine:
So anyway, I give it a 7/10.
Oh and Snowdrop was cool too... 
Watching it now.
Facial expressions don't really seem to match up too well to the voices or lines. I'm not sure if I should blame the expressions themselves or the voice direction.
Animation in general is a bit slow to start, like body parts don't accelerate fast enough or something. The puppets stretch in a skewed sort of way, like what happens when I play around too much with the Perspective tool in Gimp. Technically still much better than most fan animation, but it's hitting a sort of "uncanny valley" for me right now, where it's trying to be like the show but not polished enough. Whereas the show rarely looks like a Flash animation, this definitely does.
The voice actress for Rainbow Dash needs a better mic.
The Canterlot Wedding style cutout animation is really well done. I'm not exactly sure why they used it here, though.
Yeah. This is a lot of fan service. If that's what fan episodes are going to be, I'd really like the show to stick around. But at least it's only a couple minutes. Right?
See, the way all the buildings and trees move around after the double rainboom is what I mean when I mention skewed stretching. Like the objects are only two-dimensional but being twisted around in three-dimensional space.
What?
Why are there Power Puff Girls in my MLP fan
service episode?
I don't know what bothers me more, that this is in an animation called an MLP fan episode, or that I find it much better and more entertaining than the rest of the episode. Animation looks better, maybe because it's no longer trying to emulate MLP. The PPG are also better voiced than the mane 6 IMO. Huh. Maybe they should've billed it from the beginning as a crossover animation.
Oh look, Pinkie broke the fourth wall. The subject of 90% of fan comics.
Pre-PPG: 5/10
PPG: 8/10
Ending: 6/10
The much-anticipated animation: 7/10
As an amateur animation project: 8/10
As a project which took a team of 105 (I counted) 54 weeks to complete: 6/10
As an MLP fan episode: 5/10
Overall: Meh
It wasn't bad, but really not what it was hyped to be. I didn't like Snowflake much either, but I wasn't expecting it to be good and it was a project on a much smaller scale. So Double Rainboom was a double whammy of being meh
and a disappointment. It's too bad; I was really looking forward to the whole "keeping the show alive" thing if it ever came to that. But if this is the best we can do, I just have to hope Hasbro doesn't royally (

) screw up.