After my first full day on 10.10,
YES. Worked a lot with Adobe today (Photoshop/Illustrator) and that is painfully dragging. I've boosted the RAM/Scratch Disc settings and no change.
Trying to bring up the menu for saving images (Control+Click) - that menu pop up is lagging, or it won't come up at all. Dragging an image from an external HD to desktop to edit, sluggish. Opening images in preview I get the dreaded spinning rainbow wheel for a few seconds...then the image appears in Preview. Just feels like the entire computer is struggling.
It is a 2011 Quad Core 3.4GHz, I installed more RAM about 2 years ago (12GB total), No idea, maybe a clean install can help.
Another oddity is my volume setting, it's just louder than before. Before I had the Volume bar at 4,5. Wasn't blasting music and other sounds.
Right now I am literally at 1 volume bar and it's fine. Not a huge deal..it is running on speakers with it's own volume control - I never changed it, like I said, just odd.
On the Bright side, I actually gained space back on my HDD after installing 10.10. Roughly 900MB! Suppose Yosemite dumped a lot of old large sized unneeded Mavericks files(?)