We run both protocols across different plants and honestly the choice usually comes down to what PLC platform you're already on, not which protocol is technically better.
Siemens shop ? PROFINET, no question. The S120 drive speaks it natively, TIA Portal makes the configuration straightforward, and you get IRT (isochronous real-time) if you need deterministic cycle times for synchronized multi-axis setups. The gotcha toolndye_dave mentioned about PLC cycle time matching the drive update rate is real ? set the PROFINET send clock to match your servo task cycle (typically 2-4ms for press applications).
Rockwell shop ? EtherNet/IP. CIP motion over EtherNet/IP works well with Yaskawa and Mitsubishi drives. The SI-EP3 card anna_plc mentioned is solid. One thing to watch: the default RPI (Requested Packet Interval) for implicit messaging is often 10ms, which is fine for monitoring but too slow if you're doing any closed-loop control through the network. For pure monitoring and data collection, 10-20ms RPI is fine and reduces network load.
Practical advice: separate your press network from the plant IT network physically. We use a dedicated managed switch for each press cell with VLANs to isolate press traffic from MES/ERP traffic. The press doesn't care about your ERP queries, and your ERP doesn't need 2ms updates from the drive. A gateway device (like an Anybus or HMS) bridges the two worlds and handles protocol conversion if needed.
The data worth pulling in real-time: peak tonnage per stroke, BDC position, cycle time, motor temperature, and alarm status. Everything else (OEE calculations, trend analysis) can run on a slower polling interval from the MES side. Don't try to pull everything at servo-task speed ? you'll saturate the network for no benefit.