Guy I have no experience with the m-5. But what about the adjustable black nozzle that could be dialed down. No good?
It's not really a dialed down adjustment, it goes from a fan 60 degree spray to more of 0 degree spray. The original x-jet comes with a nozzle that can be screwed in the the x jet nozzle for light pressure application. If you go with an M-5 or x jet, first thing to do is replace the hose it comes with with a 40-50 footer so you are not having to move the bucket as much. Set your bucket up midway point that you are cleaning so you can can apply 40 feet from you bucket and them apply 40 feet past the bucket.
x jet and M-5work great for applying mixes on harder surfaces like brick, stone, hardie plank siding, concrete surfaces, etc. For softer surfaces, like vinyl or surfaces with a lot of oxidation, I would suggest down streaming or dedicated pump. And then rising very lightly.
X-jet and M-5 comes with proportioners that can help you meter the amount of mix you apply. For using basic house wash mix of SH, Soap and water, you will NOT use a proportioner. This will cause you to use way more mix than if you were to downstream.
Down Streaming to me is by far the easiest and most productive way to clean a home or building. I carry the original x jet on my truck, and do use it occasionally but rarely on homes. I use it for large buildings some times and also on driveways or larger concrete surfaces like parking lot's.