First of all, if they are both regular bedwetters you should have a plastic cover on the mattress even with the pull-ups as they may sometimes leak. Whether you use pull-ups or not is a matter of personal preference. Some kids can sleep through the night even if the sheets are wet while others will wake up and want the sheets changed. If yours are in the wake up and change the sheets category, it might be easier to stick with the pull-ups.