How has your experience been? Maybe you should give them a testimonial here, it's the least they deserve since it's serve you well (assumingly). Also, please consider giving us your perspective from a long-term user, I think you bring a unique perspective to the table!!! HTR is an oasis in this global desert of manual digitization. I did a relatively extensive search for projects a year ago, I don't remember seeing Xournal at all or maybe the old development date threw me off.

I was wondering, how do you capture handwritten notes using Xournal and Xournal++? Using some sort of tablet maybe?

Great to hear that you found out about Xournal++! It's really the power of open-source that you own your own handwritten notes as you are not locked in.