My current choices are OpenLog from Sparkfun (TTL serial), Arduino Logging Shield from adafruit (standard SD-card SPI), pure SD-card breakout, Atlas Scientific ENV32X uLog, and such.
What is the best choice in scenarios where I have to save data frequently and with as little buffering boilerplate code as possible?
What are the absolute maximum logging frequencies for serial solutions (OpenLog, etc) and SD-card via SPI?