The problem with most articles on 3D Printers is that they are over-hyped and claim that they have been advancing quickly. This article mentions the plateau in development of consumer 3D Printers that has taken place for the past couple of years. I hope that new advances do start to accelerate... 3D Printing is still much more difficult to master than it needs to be to appeal to people who are not technically proficient hobbyists.
Many 3D Printers which are actually amazing machines get negative reviews from people who have unrealistic expectations. This also results in a high return rate which makes it difficult for manufacturers to make a profit.
Thanks for posting the article and the additional information. I hope to own a 3D metal printer sometime soon.
Research 3d metal printing a bit. GE is printing turbines. It is coming to the consumer market. You print your part, stick it in the side oven to sinter it and you have something better than most machined parts. Also there are cad and solid model converters to GCode that optimize for 3D. Pick a metal from copper to steel to titanium if you want. Lab machines are about 130K with the sintering oven. Costs are rapidly dropping. It is coming. I would say 10 years and you too will be able to print your lowers.
I have a few on my Amazon wishlist.