This one is going to come down to more personal opinions than anything I'm betting. Nothing posted below is meant to be mean, just frank.
Think of what a customer is looking for:
Company A is hauling their pressure washer in the trunk of the car. (Mind you, this mode is a common subject of laughter in conversations amongst contractors) Within the trunk and back seat, are also various jugs of chemicals (none of which I would personally want riding inside a vehicle with me), an assortment of wands, and extension wand likely poking out of a window, hoses that will inevitably be all tangly and spastic and obviously no water tank - you get the picture. Charge for this customers home $150 for a house wash.
Company B is a fully self contained vehicle, logo'd looking like a rolling billboard, equipment safely stored in an appropriate place, chemicals secured properly, hoses probably on mounted hose reels, etc... Charge for this customers home $150 for a house wash or more (which they could probably get the extra because of the appearance)
Who would you call? Being in the business notwithstanding, as a housewife, I would no more hire Company A than the bum on the corner. As a housewife/consumer, I want any company that I hire to appear as professional as possible. I'm gonna ask for their certificates of insurance, references, pictures - anything to convince me that they're the best for me. When that contractor pulls up to my house - I want to see someone that looks like a pressure washing COMPANY, not a guy looking to make some fast cash. With a full blown rig operation, you will continue to "crank" out business and then some.
Again, this is a personal opinion. From our business perspective, we have gotten jobs because of our image and presentation rather than other companies in our area - and our prices are higher.