This is a beautiful test run, and it reveals two extremely interesting things!
First, let's look at the benchmark results you just generated:  
Inserts (1,000,000 items): Your C engine took ~8.03 seconds. Node.js (V8) took
~4.00 seconds. (V8 is 2x faster).
Lookups (1,000,000 items): Your C engine took ~6.73 seconds. Node.js (V8) took
0.84 seconds!
V8's hidden classes and heavily optimized string-interning dictionary lookups
are crushing the reads almost 8 times faster than the 2010-era C
implementation. That is a phenomenal performance upgrade for your virtual
machine architecture.