The fact that this machine does both R134a & 1234YF is what makes it worth every penny. Usually to do both would require separate machines and therefore, double the price. The machine is easy to use and straight forward. It comes with everything you need. It shipped out and arrived quickly.
As for any cons: The plastic cover is thin and breaks/cracks easily.
It does take 10 minutes to switch between the freon types as it clears the lines. A small price to pay..