Yes there are differences, modern regulators are mostly plastic and not very durable and tend to require alot of yearly repairs but you can get parts and service (maybe unless it is Mares). Older regulators tend to be more durable, more simple and they are made from metal but often parts (and other than self service) are problematic. Those of us who refuse to give up our old favorites scrounge parts, make parts and adapt parts from other regulators. N