been cleaning for 22 years and Truck Mounts definatly save your back. I was going to wrap it all in 3 years ago, and look path, due to back problems, and my first TM was the turning point for me. I hated the fact it kept breaking down a lot, otherwise I would still have it.
So strech yourself and enter the market running and save yourself a lot of effort, many TM user here will tell you the jobs you can't reach with a TM, you pass to a portable only cleaner,( or do with your own back up portable)
Do the job the right way, but remember "MER"= MINIMUM EFFORT REQUIRED
The jobs tough enough at times, why make it any harder ?