I usually use the MARQ connected to a chest strap a a performance comparison point for the new 6x Pro Solar. However today i decided to switch it up and do this the other way around since I'd not tested the MARQ OHR in quite some time. The results were quite good.
In this screen shot you can see that the MARQ lags a touch on the accelerations, but otherwise is really close to the chest strap I was using. This run had paces
The surges in this run were as fast as mid 4 min mile and the recovery went anywhere from walking just a touch to typical recovery shuffle.
The MARQ handled all of it well. Pretty pleased with the result and it is clear that Garmin has put some good work into this new sensor as my 5x plus doesn't handle intervals or strides well.