It has been discovered that improved polystyrene products may be obtained by polymerizing styrene in the presence of at least one multifunctional initiator that is trifunctional or tetrafunctional and at least one lower functionality initiator that is difunctional or monofunctional. These polymers may have increased Mz, increased MFI, and increased MWD. Optionally the resin may include at least one chain transfer agent, at least one cross-linking agent and/or a styrene-conjugated diene-styrene block copolymer. The presence of the multifunctional initiator tends to cause more branched structures in the polystyrene.