I use a 23C where I teach. Very easy to change between 35mm to 6x9 formats. The enlarger may be an older design but it is well built. Lens boards and negative holders are common and inexpensive. There is no heat build up to pop negatives. The neg holder is heavy. The plastic gear for elevation can degrade with time but replacements are sold as a kit. The alignment can get off if you're not careful but is easy to adjust. I prefer prints from this machine vs my LPL Dichro; but that is more a negative CI issue.