Hi
I have a 2007 MBP with 2.2GHz CPU, 128MB Nvidia 8600mGT, 6GB RAM, Samsung 830 256GB SSD.
I went from Lion to Mountain Lion last year and everything was much smoother and quicker, and the same happened here going from ML to Mavericks. Nice and fluid, no hiccups whatsoever.
The 6GB of RAM are a bit of an extra, you shouldn't need it to have a good experience with normal multitasking. I only fully use it when working with huge files, which is rare.
Average running temperatures have decreased by around 6ºC and I get 1.3 hours of battery life at half brightness, due to overall lower processor usage. I have noticed that Safari 7 is about 15% lighter on the CPU than Chrome 30.
You were mostly concerned with graphics and animations fluidity: what I have observed is that it all runs perfectly smoothly on my system.
Hope it helps