The SW in P2SH is worse in terms of:
1. It requires an additional push in scriptSig, which is not prunable in transmission, and is counted as part of the core block size
"Prunable in transmission" means that you have to include it when not sending the witnesses?
That is a name collision with UTXO set prunable. My initial thought when reading that was "but scriptSigs are inherently prunable, it is scriptPubKeys that have to be held in the UTXO database" until I saw the "in transmission" clarification.