For the Brewer's Beast kettle, that's all well and good, IF you're looking to use NPT fittings. There are drawbacks to using NPT fittings that are not present with TC fittings.
For one, fully cleaning the items is more involved than with TC fittings. If you want to take them off (which you should do at least periodically) you will need to remove the old pipe tape and apply new each time.
Another is you need to be religious about checking for leaks. Since they CAN leak if you don't do things fully correct. Sometimes it's a small drip, sometimes much more than that.
With the threads, there are more places for things to get stuck and can cause issues down the road. Not to say you'll have issues right away, but there's more risk involved. I'm sure there are tons of people that have never had an issue. I never had an issue when I was using NPT fittings, but the thought was always there (for the risk). I DID have issues with leaks at the threads though. Even when I had the couplers welded into the kettles.
Only real disadvantage of the TC fittings is cost. 1-1/2" butterfly valves typically run about $50 each. Ball valves are often less, and there are ones that are very easy to fully disassemble to clean. Far easier than what you find with the NPT ball valves (either two or three piece). Requiring zero tools to do this. I have two of those currently (one for the wort in on the MT and one at the wort out on the plate chiller).
Advantage of TC fittings is how quickly you can break down the kettle and put it all back together again. FAR faster than with the NPT fittings. You can also loosen the clamps enough to rotate fittings so that internal dip tubes (or pickup tubes) change orientation WITHOUT having any leaks. I've done this on both kettles and fermenters. The gaskets used on the TC fittings make this possible.
Not saying everyone should only use TC fittings. If your budget is too small to cover the cost, then go with NPT. I just know, from experience, how much better (IMO/IME) the setups with TC fittings are. I'm also in more of a "buy once, cry once" mind set. Granted not with everything, but with things that matter the most I am.