Method
Sisterlocks are installed with a specific tool and grid pattern as part of a defined method. Micro locs achieve similar fine sizing using interlocking or palm rolling, with freedom in the parting pattern.
Cost and maintenance
Micro locs are often slightly more affordable and can be maintained with a wider range of techniques. Both need retightening roughly every 4 to 6 weeks.
Choosing between them
If a specific grid and method matter to you, choose Sisterlocks. If you want fine locs with more flexibility in parting and budget, micro locs are an excellent choice.