That is impressive. I love both our HO (the medium and the large fit Iris well), but can only get them to last 3 hours. I wasn't as mindful of the clock as I should have been this morning and left her in one for 3 and a half hours and we had compression wicking.
But I can't get anything to last Missy longer than 3 hours, so that's no slight against HO nappies.
And they're lovely to look at, too! Just bought a newborn sized one for a pregnant friend in the hope of converting her to cloth. FC!