Optimization to / such that the & more version expands to equivalent of (/ x (reduce * y more)) rather than (reduce / (/ x y) more). There should be an inlined variant of & more as well.
This was originally part of CLJ-184, but was pulled out because it's big enough to be its own ticket. The rationale is that multiplies are significantly faster than divides on the JVM, and n-ary calls to / could be faster.
See "Java Multiplication (Much) Faster than Division" for background and Java benchmarks.