Disclosure - we built this.
We are developing some ACME tools and as we are curious about LetsEncrypt performance, we built online monitoring as a validation tool.
If you find it useful - good. If you think it’s lacking something - even better, especially if you let us know.
We issue and measure 8 certs/minute across 4 locations (prod) and 20 certs / minute across 5 locations (staging). Timing measurements are for each API call separately. The library has an OCSP client but no data collection yet for that.
You can also get weekly email reports.
Update 1: June 27, 16:15UTC - upgraded monitoring servers, improved caching, optimized access to speed up data collection, corrected visualization of downtimes (we initially assumed that downtime = no API response … how silly of us).
Update 2: We have detected the first downtime on 25th - 11 minutes before the official detection.