The extra day off is probably equivalent to getting paid ? Last time I had on-call part of the job, I think the pay increase for standby would have amounted to roughly 8h as well (actual interventions were also 150% for regular nights and Saturday, 200% for Saturday night and Sunday)

Lugging around a laptop and the on-call phone when going anywhere, checking every now and then when the phone was not with your for a while (e.g. pool, gym etc), making sure you don't go places with no signal was enough of a PITA that knowing we were paid every hour of that had a nice psychological effect.