I see quite a few of the pro detailers use foam guns, I assume for the purpose of getting more lubrication for washing. How beneficial is this to the car over, say, no bubbles? Is it something I should strive for?

And is it something I can approximate by using a jet into the wash bucket?

I'd guess I have about 3-4 more washes at least with this OTC wash before I get into the ONR that I just ordered.

Most OTC washes if they are good quality or the gel lubricate well. The foam guns are used to presoak and soften/loosen grime.

I never use the recommended amount .. I use more and fill the pail 3/4 with hot water then a hard stream from the hose to foam it more.

I think its a good idea, but I think the gun itself is waaaaaay overpriced. Last I saw one at autogeek it was $60.00? Cmon, thats ridiculous....Even if its on sale, shipping depletes the reduced price. Too much for too little. JMO

Oh, I wasn't going to buy a gun.

I guess I veered from the actual question on that one. I guess what your asking is suds over just actual water or non suds, like NRWS. The actual purpose of a sud or bubble it to lift and encapsulate. It does have benefit, just dont let them dry!