Just a benchmark to measure performance of Set(), Map() versus Object.create(null).

Run the benchmark for your current browser: https://gorhill.github.io/obj-vs-set-vs-map/.

Chromium v51:

• Adding items:
  • Obj set() x 27.38 ops/sec ±6.75% (50 runs sampled)
  • Set set() x 83.31 ops/sec ±3.47% (70 runs sampled)
  • Map set() x 68.24 ops/sec ±3.12% (69 runs sampled)
• Looking up items (80% misses):
  • Obj get() x 10,516 ops/sec ±0.30% (93 runs sampled)
  • Set get() x 17,429 ops/sec ±0.51% (94 runs sampled)
  • Map get() x 15,462 ops/sec ±0.35% (96 runs sampled)