I started raising wagyu about 13 years ago. I had a few Angus at the time and learned about the health factors in wagyu beef versus other protein sources. I eventually built a good lineage that now produces much of the sought after qualities. As a consequence, I learned a lot about the breed. I always favored Angus and Angus crosses with Hereford and/or Holstein cattle before I learned about wagyu. It made great product that I always sold at a decent price. I can say that Wagyu, especially full-blood and purebred, make even better product and at the same costs as raising my previous non-wagyu cattle. They take a bit longer, but most of that extension of time is to get the tenderness and marbling fineness desired. I get similar yields as I did on Angus too. (725 to 850 lbs. hanging weight)
The tenderness, marbling and fat content is definitely much healthier meat than you can produce with any crosses of other beef breeds. You can control the finishing to achieve composition anywhere from prime, BMS 4 (like prime Angus, but with healthier fat) to BMS 10-12 like Kobe. The DNA for both Tenderness and marbling is a dominant DNA trait in wagyu. DNA meat quality genetics is 30 to 40% of the meat quality, the rest is how they are raised and the finishing technique/mix. I found that most can be finished (1100 to 1400 lbs.) in 20 to 28 months of age, depending primarily on the quality you're after. Be glad to offer more detail if there is any interest.
Here are some pictures of finished. First 2 pictures were pushed to BMS 10, making it like A5 Kobe. They were sold during the Memorial Golf Tournament a couple of years ago. The third picture was finished to be more like a BMS 7 to match a texture and flavor similar to very high-end Angus, but with the Wagyu health factor.