I am a firm believer in adding a sporlan filter drier to all systems at the air handler. That being said i would not expect and non-refer man to think the only way to remove moisture from a system is thru a vac pump. I have had systems so full of water that you had to hammer the pipes to move the ice blockage which you could hear banging down the pipe to the rack. You know the system cleaned up fine and we never put a vac pump on it. I have also had small systems (under 1 h.p) that have had moisture problems (moisture freezing in TXV)which were solved with no micron gauge or the customer having to pull the cooler of all his product. This is all achieved thru filter drier technology. I do believe the most importent thing to do is remove all non-condensables and have a relatively clean system and a good filter drier. I am not saying that a good dry system is not assured using a micron gauge and nitrogen, but good refrigeration practices can be achieved with non of the hype. I have a supco micron gauge i have used a few times on troubled systems that had severe moisture contamination caused by a broken H20 evap loop but thats about it.
When i talk of small systems I am refering to any system under 5 tons.