Handoff lets you continue your current task on another device, from where you left off (it hands off the task). So if you have a text document open or you're writing an email on a mac, it will let you continue doing that on an iphone, with the text you entered on the mac already being there.
You can also make calls or send texts from a mac if your iphone is nearby.
IIRC a bug causes the CPU to sit at 100% constantly, that's why the fan runs at max. A sleep-wake cycle after boot temporarily fixes that problem and the battery life increases.
I started with a Digilent Basys2[0], it could be a slightly cheaper alternative to the Terasic DE0. It uses a Xilinx chip, has a free design/development software called ISE Webpack, which also has schematic diagram support.
Unfortunately, it still relies on the same Xilinx ISE (webpack is sufficient), so, it's not possible to cook bitfiles on the Pi itself. But the board itself is nice, easily programmable via SPI, has a decent Spartan6 LX9.
You can also make calls or send texts from a mac if your iphone is nearby.