The one without a cup is a Finex fx3000 that I need to get a cup. It was given to me by my painting buddy who painted my Camaro. He said it’s a good gun but he upgraded to a newer model is all. The one he paints with now is a $3,000 gun.
Cody, that's a good collection of spray guns. The Finex is in the $200 range and should do a better job controlling the flow of paint than the Harbor Freight one (nothing wrong with the HF guns). He probably bought this set of Sata guns:
THREE TIMES 100 FOR A PERFECT FINISH! Complete your 100-Year collection now! The SATAminijet 4400 B and the SATAjet 100 B are also available in the 100 Years anniversary design. With the compact spray gun for small surfaces and spot repair, and the perfect spray gun for primers and fillers...
www.dipyourcar.com
I painted our first house with a Craftsman spray gun that a friend gave me. Pressure feed and I had to thin the latex paint about 50%. Waving that quart of paint back and forth (and up and down) wore me out. Over the years I ended up with a variety of regulators.

When our '71 Vega GT rusted out, I sculpted a bunch of fiberglass and painted the car with the original Acrylic paint in 1976. I bought a Harbor Freight 2-quart remote tank and gun to lighten the weight in my hand. It came out better than I expected and I was able to give the car away guilt free a year later to a coworker who need transportation. I replaced the Vega with a '69 427 4-speed Corvette convertible in a similar color.

Every thing I do involves mistakes. For our 25th Anniversary in 1987 I wanted to buy two silver cars. Found a year-old Dodge 600 turbo convertible and an 8-year gray market BMW 733i. The BMW had a couple of rust spots on the top of the front fenders. I didn't buy a welder for another 20 years so it was once again a fiberglass/resin patch job. Sanded the whole car down and primed it with lacquer primer. Sprayed several coats of BMW silver on the primer and it looked pretty good (painting over the black front and rear valances with silver helped). A couple of coats of clear and it was nice and shiny and good to go. I bought a better set of spray guns (DeVilbiss FinishlLine kit with full and detail size gravity feed guns and accessories) and started using disposable (DeVilbiss DeKups) paint cups in 9- and 24-ounce sizes. I adopted the disposable cup system because I was spending too much money and time cleaning the aluminum (and plastic) cups that came with the guns. Worse than that, the aluminum and plastic cups had no name on them so I had to search through the cabinet where they were supposed to be stored and then go looking for the one that someone stored somewhere else.

Two two years later the paint started blistering. I failed to put hardener in the primer and the two part silver and clear coat reacted with it. I was going to re-paint it but left for Australia instead.
I am not a great painter but I knew the basics and helped a friend paint his basket case 1959 Corvette. He did all the fiberglass repair, filler, primer and prep work and then I helped him spray and sand a dozen or two coats of black lacquer in his garage. The Corvette won first place at World of Wheels in the Modified Sports car class.

Hoping for at least that good a job on my '72 Corvette, I bought a much better spray gun for the finish coats in 2009. Paid just under $400 for an Anest Iwata LPH400 gun. Suddenly my painting got better, a lot better. A close examination of the tip shows the Iwata having a machined flower petal shape that spins and disperses the paint better than the tips on cheaper guns.

I may have gotten carried away. I bought that same green Vaper hose gun (spray isn't an accurate description), an Anest Iwata LPH80 detail gun and a Sata Jet 2000 Digital (all HVLP).

The Sata Jet was a salvage job. Bought it for $100 and spent several weeks doing chemistry experiments on it to get rid of the petrified paint from its internal passages. Looked like it was just used every day without ever cleaning it. When it stopped spraying paint of any kind, it was just sold on eBay for a fraction of its value. I prefer the Iwata guns but at least now I know what all the Sata fuss is about.