Length is faster than count
Length is faster than count

```
Warming up --------------------------------------
              count
   317.318k i/100ms
              length   329.512k i/100ms
              size     329.953k i/100ms
Calculating -------------------------------------
              count       9.806M (± 7.7%) i/s -     48.867M in   5.014627s
              length     11.696M (± 6.3%) i/s -     58.324M in   5.008040s
              size       11.074M (± 7.5%) i/s -     55.102M in   5.005626s
```

eileencodes/sprockets,rails/sprockets,recursecenter/sprockets