The Little Bee 30A ESC is exactly what you are looking for in a lightweight, super powerful speed controller.
Little Bee uses a Silabs processor and fast dedicated driver chips. It comes flashed with BLHeli-S Firmware utilizing Oneshot125 communication protocol making it fast and responsive to throttle movements.
• Small size
• Preflashed with BLHeli-S Firmware
• Silabs MCU EFM8BB21F16 running at 48MHz
• Dedicated driver chip
• 2-6s LiPoly
• OPTO ESC
Input: 2-6s LiPoly
BEC: No BEC, OPTO only
Dimensions: 35 x 17 x 3mm
Weight: 9g (with power and signal wires)
Note: this is an OPTO ESC so you will need a 5V BEC to power your flight controller.