Look at the label. Lucas fuel additive is labelled first and foremost as Upper Cylinder Lubricant, not an injector cleaner.
Many people report their butt dyno feels that their engine runs smoother after adding additive xyz, but then in the next tank the effect is gone. These folk are probably feeling the benefits of the UCL rather than anything getting cleaned (it makes no sense that "cleaned" injectors are immediately gunked up within a gallon of their untreated fuel).
So if what you want is a UCL, then the lucas product is what you should get. It is priced right, especially at the gallon size.
If you're buying Lucas UCL thinking it's going to do a ton of cleaning, then that's on you for buying the wrong product.
That's like buying a no fat, frozen yogurt and wondering why it doesn't taste as smooth and creamy as ice cream.