My experience with it is that Quadrant (and the Media Player) are both much slower at decoding H.264 video with Opencore. Stagefright does H.264 decodes WAY more efficiently... so the Quad scores are higher.
And video playback is way smoother. It isn't JUST quad scores, folks: some of us experience unbearable video stuttering with the new media engine.
Long answer: video decoding is hugely CPU intensive. That's why its used as part of the CPU testing scheme. Since Opencore is several orders of magnitude slower at decoding h.264 it badly skews the overall quadrant score. The rest of the phone is just as snappy as Sapphire at its best normally is, but the wretched video decoding score drags its down.
For folks who don't watch the kind of video that Opencore has trouble with it won't make any difference in how fast and snappy the phone is. For those who do watch those videos (like me) its a problem. Switching back to Stagefright fixes it.
I haven't tested Pandora on Sapphire 1.0 with Stagefright, though. I've never had any trouble with it so I'll keep my fingers crossed and hope...