Not necessarily. The Rigid tool is used to make single wall flares
at a 37º angle in seamless tubing. The connection has to be supported with a tube sleeve (
https://secure.chassisshop.com/partlist/15920/ ) and then a tube nut of the correct size. These are used to plumb a brake system with AN fittings. I have one of these tools and used it to do my race car in AN fittings and stainless steel seamless tubing.
The Mastercool kit is awesome and its strongest suit is that you can use it anywhere on the car rather than having to remove a line and carry it to the vice to connect an existing line to a new line. It also forms many quick connect fuel lines,etc. The only down side to it is that the clamping pieces have a heavy knurl,and will leave some of that showing behind the tube nut. It is a non-issue for normal shop repairs,but might not look as nice on a custom/show vehicle.
I like the Eastman type tool the best. It is fast and makes nice looking flares without the knurl where it clamps the line. I especially like that when using the softer copper/nickel line we use in the rust belt. The Eastman tool wasn't around when I bought my flaring tool,but I have one very similar. It came from Fed Hill Trading Company.
https://cunifer.com/hikashop-menu-fo...-flaring-tools
For those unfamiliar,Cunifer is the trade name of the original UK sourced copper-nickel brake line. It gets its name from copper (Cu),nickel (ni) and ferrous (fer).
It is considerably more expensive then the Eastman,and kind of pricy to keep adding capability to as well. For the person doing their own repairs and restorations,I think the Eastman would make the best overall tool.