Perhaps my terminology is incorrect. Sorry. In the first shipment, rather than receiving Red Oak (pumpernickle colour), I received White Oak, Birch and something else, I don't remember. In addition to the different types of wood (or species?), the planks were all different widths and depths. Some were 3" wide, some more than 3" wide and the grooves on the bottom of the planks were different from plank to plank so the planks did not line up and fit together. Some were higher than others. I understand that wood is a natural product and never perfect. That is the beauty of it. I respect that. But when the pieces don't come from the same tree, are stained differently and don't line up, I think the end product on the floor is quite imperfect. As for the 72 hours acclimation period in my house, this is what the manufacturer instructed me to do. I don't know if that's enough time or not, I just followed his directions. Yes, this is solid hardwood flooring that I ordered and paid for. Did a few engineered pieces slip in somehow, who knows? The installers were very upset with the product and couldn't believe what they saw when they opened the boxes. There is one large master bedroom and a walk in closet left to lay. The majority of the wood laid in the hallway and second bedroom is acceptable. I do see some planks thrown in here and there that do not belong because they are white oak or the wrong size. Yes, there are some gaps between a few of the planks which I noticed when I wiped the floor with a cloth. I'm prepared to live with these inconsistencies because I can't imagine having it all ripped out and tossed into the garbage. The manufacturer has not responded to my phone calls or e-mail today. I have left him a message and given him until the end of this week to complete the job. Failing this, I'm afraid I will have to take legal action. I looked into consumer protection and understand my rights. The manufacturer is no longer a member of WWFA. As for paying the installers, how can I treat them unfairly for something they are not responsible for? I'm going to work tomorrow because I can't afford to take any more time off.