As Arthur noticed some of the "/index" cases -- very roughly, most of the test cases examples are written with the */index version of the procedure in mind, but are shown relative to the non-index version.

The test case for vector-append-subvectors - the "0 2" arguments mean only #(a b) is extracted from the first vector, not #(a b c).   So change "0 2" to "0 3" or change the expected result to #(a b h i).

(vector-binary-search vec value cmp) ==> not specified what index is returned in the cases of ties - are any matching indices acceptable?  The least, the greatest?

Text for reverse-list->vector, "but the resulting LIST contains the elements in reverse..." -- should be VECTOR.

In the spec for make-vector, the word "optionally" is misleading.  The vector is always filled with FILL, whether the value is supplied by the caller or not.

The "fill" functionality in vector-copy seems like a bad idea to me.   It is conflating a copy operation with an append operation with a filled vector.   No other copying procedure in this SRFI includes a fill argument.    The fill value has an unspecified default value per the specification, meaning filling occurs whether a fill argument is supplied or not -- so even the 3 argument version of this procedure is not equivalent to the R7RS-small version.  The incompatibility with R7RS-small's vector-copy forces an implementor to have to choose whether to add this feature to the base vector-copy, or force users to have to choose which version of vector-copy to use in their programs...

     (import (scheme base) (except (srfi 133) vector-copy))

OR

     (import (except (scheme base) vector-copy) (srfi 133))

I suspect some will say that since the fill functionality only covers situations that are "is an error" to the R7RS-small case, there's no conflict, and a single re-exported binding is legitimate.    I dislike this rationale because it forces the implementor to sacrifice useful bounds checking and error reporting in the R7RS-small case.