I like the idea that MCFC has on a way to combine the two and not lose twice as much flow. If we use two different sets of fittings we run the risk of losing lots more flow. Look at a fitting that goes inside a tube and compare the inside diameters of the fitting with the tube and you see why.
I do lots of PVC plumbing, both inside and outside in wet and do have one thought. I do not use purple primer on most occasions! It does soften the PVC and does make for a better joint but most of the time we don't need it and it does add to both the effort and downgrades the appearance.
When I do use primer is if I have old PVC that has degraded a bit and has a layer of "corrosion" or if I am working in a hole where water is shooting out and everything is cold and wet. Difficult conditions or high pressure, use all the tools but that is not true for many of our tank uses.