|Raspberry Pi 0||ARMv6||512 MB LPDDR2||obsolete: high power consumption, weak CPU.|
|Raspberry Pi 1||ARMv6||512 MB LPDDR2||obsolete: high power consumption, weak CPU.|
|Raspberry Pi 2||ARMv7||1 GB LPDDR2||obsolete: old CPU compared to Raspberry Pi 3, no onboard wireless.|
|Raspberry Pi 3||ARMv8||1 GB LPDDR2||excellent quad-core CPU, GPU, onboard Bluetooth/Wifi.|
The Raspberry Pi 2 benchmarks and Raspberry Pi 3 benchmarks are very impressive and show far faster performance than the Raspberry Pi 1/0. Using the graphical desktop, the Raspberry Pi 3 is useful for basic desktop use.
Beaglebone Black had been a much better choice than the Raspberry Pi 1 due in part to the PRU DDR3L RAM (faster), and ARMv7 CPU nearly twice as powerful as the Raspberry Pi Zero/1, native Ethernet, onboard SSD (eMMC), better onboard I/O (for local sensors), etc.
Intel Edison was a better choice for energy-budget conscious tasks than the Raspberry Pi and the Beaglebone Black due to the Edison’s dual-core x86 CPU, fast RAM, and extremely favorable Intel Edison energy efficiency. Depending on your application, the Edison may have run 10-20x as long or more on battery than the Raspberry Pi (1, 2 or 3) and Beaglebone Black.
My opinion on the original Raspberry Pi (non +, model B 256MB and 512MB RAM) boards was fairly limited due to the anemic ARMv6 single core CPU of the Raspberry Pi 1.