A pruned node is a complete node. "Complete node" means to fully validate and enforce the Bitcoin rule. Pruning simply means that the node does not bother to keep old historical data that is never used at all, except to help the new nodes synchronize, the wallets and the like are rediscovered.
Pruning will not affect the validation performance, apart from the fact that there may be some small latency peaks created by the periodic elimination of old block files, or small latency improvements for not participating in the feeding of historic blocks to new colleagues. synchronization.