That's actually reassuring to hear. Aside from Chilli, it's the only program I've ever used (12 years going). I've got teamates pushing for changes but jira comes at a high cost. Redmine may look old and I hate that it's written on ruby, but it's free and with some plugins it's been able to suite our needs well.
I use both Redmine and Jira at work. I don't know if we're using an older version but Redmine feels like something from 2001. Even the API for it is unpleasant.
I find it an active hindrance to my work. To the point where I have written tools to read data from it via the API rather than use its infuriating interface.
I'm glad it works for you but to me it's a bit too minimalist. Its user interface is comparable to the forums I was using in 2002. I'd rather something more akin to the ones I was using in 2006.