The finite solvable groups G whose commutator subgroup G' is nilpotent, look interesting to me (in view of the easy structure of finite nilpotent groups and the resemblance with solvable Lie algebras in char. 0). Let me call such groups perfectly solvable. Note that the finite supersolvable groups (groups with cyclic normal series) are perfectly solvable.
Have such groups been studied in Literature ? Thank you.