Ridiculously easy to use! The only external component you need is a 3 mm jack to get it working. Audio is perfect with headphones.
Just remember to set the CLOCKF register to 0x8000 to double up the clock speed or else your sound will come out at half speed.
SPI clock speed can't be faster than 3 MHz, I was running an 8 MHz AVR with SPI2X set (meaning 4 MHz SCLK speed) and the decoder would behave erratically.
You can power this with 3.3 V, the regulators on board dropped my voltage from 3.29 V to 3.24 V. My entire setup ran on 3.3 V so I didn't even need any level shifting.

I don't get it, the breakout board with the IC costs the same as the IC on its own?

VLSI has minimum advertised pricing on their ICs (forces up the IC retail price). We can build the dev board for much cheaper so we decided to keep the retail price low on the board.

Yep, it's a mystery, though it may have to do with the fact that the VS1002 has been discontinued by VLSI.
The board comes fully populated and ready to run. I've just received mine and will be trying to make sounds this week.
I'm using this with a 5V MCU, so I'll need level shifters. This means I have to have my own 3.3V supply just for the level shifters. It would have been handy if the on-board 3.3V digital supply had been brought out to power the shifters.