inconsistent handling of arrays in structs

[3b]

(asdf:load-system 'cffi)

(cffi:defcstruct (v3 :class v3)
  (x :float)
  (y :float)
  (z :float))

(cffi:defcstruct v3x2
  (c :char :count 2)
  (v (:struct v3) :count 2))

(cffi:with-foreign-object (x '(:struct v3x2))
  (list (cffi:mem-ref x '(:struct v3x2))
        :c (cffi:foreign-slot-value x '(:struct v3x2) 'c)
        :v (cffi:foreign-slot-value x '(:struct v3x2) 'v)))

=->

((V (Z 0.0 Y 4.2038954e-43 X 0.0)
  C #.(SB-SYS:INT-SAP #X7FFFD68CFFD8))
 :C #.(SB-SYS:INT-SAP #X7FFFD68CFFD8)
 :V (Z 0.0 Y 4.2038954e-43 X 0.0))

expected either SAP for both V and C, or preferably a lisp sequence of 2 elements for each.