Yes, I got it done and it worked for my car. This is from another thread where I posted it:
"Ok, so the update I was promising on the TSB148 fix. My car was at the dealer for about a week because some parts had to be ordered from L.A. (apparently someone stole the last part from Chicago just before my order was put in lol). I asked them to also change my oil and do the 15k mi service so I really wasn't worried. What DID get was the fact that when I did get a rental Enterprise gave me a Fiesta... I'm not a big guy but my shin was resting on the center console near the shifter. I didn't mind because originally it was going to take 3 days. When I got the call stating it would probably be a week I told them I needed an upgrade. After some calls around between dealership and consumer affairs (rentals are taken care of by Kia, not dealership) I got an Altima as a loaner from the dealer that just got back in. I also got a call from the service manager saying that the 15k service would be $200 after my service plan was taken into consideration. That didn't sound right and after another call to consumer affairs it was taken care of and all in all everything was the normal $10 for just the Techron being added.
Sorry for the big wall there, here is the TSB148 portion. They said this job took about 9 hrs to do after all the parts were in. I think there were like 20 summod parts replaced. The car now starts VERY smooth and there is absolutely no rattle at all. This is exactly the way I would expect a car of our caliber to start. I highly recommend this service to anyone on their next standard service interval (beware parts may be limited and you may be without your car for a bit, so plan accordingly).
TL;DR
Kia consumer affairs did awesome for me again and TSB148 is worth it, my car starts great now. "
Here is the thread. Also gave a quick status for 1 month later.
http://www.cadenzaforum.com/forum/new-2014-cadenza-general-discussion-forum/33609-new-cadenza-2.html