I recently switched supply houses and the new supply house carries EPC fittings. I have noticed a huge difference between these EPC fitting and the Nibco and Muller fittings that i used to get from the previous supply house. The EPC Tee's have very deep, pronounced lines on the sides from the process they use to wrot the fittings. On the larger fittings, these lines also appear as deformations on the inside of the Tees and I am wondering if they can cause increased turbulance. On the 3/4" and 1/2" the insides dont appear to be deformed, just the outside. The Nibco and Muller fittings are smooth. Secondly, the EPC fittings have a dull mottled look, they are not bright copper like the Nibco and Muller so I wonder if Elkhart uses a different type of copper to make their fittings. I have used many other fittings in the past which were tarnished from age and that never bothered me as it never took any longer to clean than the bright new fittings, but these EPC fittings are more than just tarnished. Strangely, the 1/2" fittings are not really dull, they have a pinkish pickled look like they were cleaned somehow. The counter guy says thats how they always look. Any thoughts on EPC fittings? They are made in the US and I'm probably just overthinking this. They seem to fit fine, no dimensional issues. By the way, these are solder fittigns, not press fittings. Thanks in advance for any comments.