OK, I can't help it anymore......
1. Why would anyone use a costly truck mount and its fuel to apply protector?
2. Please convince me that every operator (including tired/distracted owners) will completely purge their cleaner/rinse agent from the machine and solution lines before they "snap on the jug).
3. Depending on your machine and solution hose type, you may have noted that some ugly stuff builds up in hoses and heat exchangers that probably shouldn't be mixed with protector and left on the carpet.
4. Unless you are very careful, most in line sprayers can leave overspray on items that you do NOT want to have protector dry on. Its easy to clean up after some prespray or deodorizer. Protector does not wipe off of wood or painted surfaces. Think more in terms of steel wool and refinish/repaint in these instances.
Thank you. I feel better now.