The pipe was upgraded as you mentioned. The tank included the smoke tank, which I use for extra fuel. I get a nice 10 minute ride with the K160. All the tank fittings came with it. But, I up graded to Hi-Flow fittings and clunks, etc. I think the basic gear was upgraded also. Not sure on that as I got the Electric Gear and it was significantly improved from the initial OEM Air and E Gear. I think they may have provided a bit heavier hardware also. But I am not sure about that either as the stuff I got was great. But initially I heard some gripes about the hardware. But, I think most of the remaining increase has to do with tariffs and it may have been just priced too low to start with.
Never seen a manual, ... yet. But if you go to CARF and get a manual for a Flash or Ultra Flash, the basic building process, is the same. Start at the back and work forward, etc. There are no instructions for the Landing Gear Controller and Nav Light Controller either. I could not get either to work correctly. They may have worked. But after days trying to figure them out, they were replaced.
Bottom Line: I love the jet. It is easy to fly and see. No unexpected tendencies. Didn't need to mess with hours put into making the cockpit look good! Was delivered a couple days before the promise of 8 weeks and came in a very sturdy box w/o any sign of shipping damage. When I had questions about the Landing Light and Nav lights, Dirk provided some specific instructions and the Landing Light worked great. But the other lights did not because the factory installed LED controls in the harnesses and tried to make them work with a controller too. One LED was DOA on arrival. But Dirk gave me my $s back for the Nav Light System, and I put in another Nav Light System. So, overall, the service from Pacific RC was great.
The Electric LGC is very basic. No ABS, and it would not work consistently proportionally. In the Electric Gear, they have permanent magnets in the Hubs to draw the floating disk back off the electromagnet. What happens is; you have to give it almost full braking to get the floating disk moving and then once it moves off the permanent magnets, the brakes lock up. Then you back off on the slider and then braking is proportional. PITA doing the brake dance and is hard on the tires, etc.. I removed the magnets and added and Zicoy LGC 15. We'll soon see how that works. Can't tell you how well the air systems work. But there are a lot of them out there and there is plenty of space in the jet for the cans.