Intel Galileo
Key Features:
Type: Single-Board Computer
CPU: Intel Quark X1000
Speed: 400 MHz
OS: Yocto Linux 1.4
RAM: 512 KB SRAM, 256 MB DRAM upon 8 MB Flash Memory
Storage : MicroSD (32GB), USB
Other Features:
WiFi : mPCIe Slot
Bluetooth: N/A
Ethernet: 10/100 MB
Analog Pins: 12
Pin Logic: 3V3, 5V
So, if a higher pin logic or more number of analog pins or an Ethernet connection come under your list of requirements, then you should definitely go with the Intel Galileo.
Intel Edison
Key Features:
Type: Tiny Board Computer
CPU: Intel® Atom 2-Core - dual core, dual threaded Intel ATOM x86 CPU consisting a 32-bit Intel Quark Micro-controller running at 100 MHz
Speed: 500 MHz
OS: Yocto Linux 1.6
RAM: 1GB LPDDR3
Storage : 4GB EMMC, MicroSD card(Arduino)
Other Features:
WiFi : 802.11 a/b/g/n
Bluetooth: 4.0 LE
Ethernet: N/A
Analog Pins: 6
Pin Logic: 1.8V
Hence, for Bluetooth or a faster WiFi, the Intel Edison should be your go-to board. Also, it has a higher processing speed with a more powerful CPU and RAM. Plus, it comes with more flexibility as you can use it with Arduino board while prototyping and even with smaller breakout board while deploying according to the requirement of your applications. So, Intel Edison is definitely the better board in terms of their overall features, which is quite understandable as it is a product of an extra year of research and technological advancements by Intel.