I have not paid for an open access publication - but I do review for and I am an Associate Editor for open access journals.
Due to 'predatory journals' - you have to do your home work and identify if you might not be paying money to one. The Directory of Open Access Journals (DOAJ) site is a good one to check.
If you target a legitimate OA journal i.e. Biomedical Central (BMC) journals - then the experience is usually a good one.
Well, if the publisher is trusted and well-indexed, then it really depends on your resources. For universities that can pay, the open access choice is really a good option for their authors as they increase the work visibility and transparency.
Its not always the case that journals that charge APC are predatory. I have paid minimal APC for some trusted journals and also paid no money for some of the trusted OA journals. We just have to do a thorough background check of the journal we intend submitting our research. Best regards
Nowadays certain prestigious journals ,which pay their reviewers, charge a certain fee for publishing papers. When the prodeeedings dominating the publication process are meticulously observed and when the editorial board are great scholars of the field , then the payment of a fee should not be regarded as a vice. It is the quality that counts , a thing which is absent in predatory journals.