We have 7.28 kWp facing straight south with a 25° roof. We limited it to 70%, but with the possibility to first subtract self-consumption and only then limit it to 70%. So if the system would normally be throttled at 5.3 kW, but we are currently consuming 2000 W, it won’t be throttled at all.
Additional costs are the larger inverter (ours is 7.5 kW) and the Solarlog, which we would have bought anyway, and an S0 meter that cost 40 euros and still serves well. With the S0 meter and the Solarlog, we can now see exactly when how much electricity is consumed down to the minute and view daily profiles, which has already uncovered some major energy guzzlers. There are also many infos (self-consumption ratio, graphics, daily production).
Conclusion after one year: hard throttling at 70% causes losses (which hurt more psychologically than financially), but none at 80%. So I would choose the next inverter so that 80% of the installed capacity is covered; ours is a bit too large. A 6 kW inverter would have sufficed completely, because we only exceed 6 kW when it’s cold but sunny, i.e. in spring.
However, I wouldn’t want to do without the Solarlog and S0 meter anymore. So: soft 70% rule!