Hi Tom - you bring up a good topic - I am hopeful others will chime in here and share their own experiences, so we all can 'compare notes', so-to-speak.
There have been some discussions, right here on COPD.net, which focus on varying aspects of humidifiers and humidification, which I thought might be of interest to you. For your convenience, here is a link to several of those articles/posts: https://copd.net/search?s=humidifiers.
I do hope you find them to be helpful.
All the best,
Leon (site moderator COPD.net)