Being a GFX artist my compositions usually take hours to render, so definitely excited about the multi-frame rendering, however I gave it a test drive today and the Beta version only rendered a few seconds faster than the single frame rendering, hoping when they launch it, it will be faster than it currently is.
One amazing thing is being able to get notifications once your queue is finished! BIG UPS ON THAT!! No more constantly going back to the computer to check your queue, one question on my mind is, will it let you now if the queue fails to render?
If you're not seeing much improvement with MFR, it'd be great if you could share your project with us. Email it to firstname.lastname@example.org. If you can't, I'd suggest looking at the effects you're using in your composition. If those have a yellow warning icon, that means the effect is not optimized for MFR. While MFR will still be working, each frame that is using a non-MFR'd effect will need to wait for another frame to complete rendering with that effect. A good number of partners have already started shipping MFR supported effects (BorisFX, Red Giant, FxFactory, Revision FX, etc.) so you may be able to find updated plugins already.