Many many years ago (about 15) Hydramaster UK did some work for us on our Prochem CUB XL. He applied the bandage wrap to that machine and the heat difference was surprising. Since then i have used it on many different truckmounts. When people ask me to service their machines i advise they have it done as part of the service if it dont have any on. Most have it done and are surprised at the heat gain. It surprises me that Prochem never used it on their machines. One thing you should not do though is over apply the bandage. This can cause the exhaust to get to hot and crack. So, just overlap by about 50% and it will be fine.
We ran a Hydramaster Crossfire 4.2, the heat exchangers on that machine stand vertical at the rear of the machine. This means the exhaust from the engine to the heat exchangers was about 1 metre long. Without exhaust heat wrap the machine water temps were not very stable and held approx 185 degrees. When we applied the exhaust bandage wrap the water temps were stable and we were getting water temps holding at between 220 - 240 degrees. Thats a huge difference.
If you order the exhaust wrap its better to order to much than not enough so get 10 metres. In time the wrap does degrade so the spare length wont go to waste. Re,ember, wrap from right by the engine all the way to the heat exchanger.