I have experience with both Ford 460 and Ford V10 310 HP.
I had Camping World install for the 460 in a Coachmen 35ft Mirada. I was happy with it completely except I DID NOT get the increase in MPG they suggested. Why Not, since I had more power I used it and using more power also uses more gas.
The V10 was is in a Winnebago 35U installed at the Banks factory in Azusa, CA. The complete system includes a Transcom and an Automind chips. They do 2 units each morning at the factory. I was happy with the work. It was about $3100.
We drove back to the High Desert (Hesperia) It struggled to climb Cajon Pass and the next morning it was hard to start and kept dying like it was flooding the engine. After a few tries it started and ran fine until I went down in a valley and up the other side. It died at the top. A few more tries and it ran ok.
I called Banks and they told me the Automind chip was defective. They sent a new one over night to a dealer near me and they installed it the next day. I went on my merry way.
A couple months or so I received a letter from Banks telling me that I had not returned the defective chip and unless I did they would bill my credit card for approx $400.
I had a nice conversation with the accounting lady and told her she could not do that since I had only authorized the card for the installation only and also they had not sent the chip TO ME but to the dealer.
I did not hear anymore from them.
I am very happy with the results and the same comments apply on the MPG.
Also to the person that had nothing good to say about their experience, I think they probably were told that the Oil Leakage had nothing to do with the work that was done unless there is an oil line close that was damaged. I hope the leak has been repaired and a response will be printed here.