I'm not involved in hydroseeding and know very little about its application but comparing your pictures to what I see around my area, many of the companies here seem to apply maybe 1/3 of product you do. Meaning instead of the area looking quite green after spraying it is still very brown and sparse? Assuming there are rates explained on the product for sqft do you apply at that or less or more?
Sorry if you already made mention of this but how fast (as in yards per hour or whatever time measurement) can you apply mulch with the blower? Obviously you need a lot of work to make the machine worth while but seems like that can be quicker and much less labor intensive. But again need the work to support the cost of the machine.
Your work looks fantastic and your business seems to be really moving!!