I will add my pennies worth.
I use the Omnivac a huge amount. It is one of the best tools I have ever bought. I have several modified tools all made by Glyn at Omnipole. I have several large commercial contracts because of this machine!
I clean up to 3 stories on my own with no problems and after that to 48 I use another person with a support pole. But most large commercial jobs will require a cherry picker for guttering above roofs etc and any vac system just wont work because of impossible access (see pic)

To be honest if its 4 stories or above I will have a cherry picker on site.
I have a possible job coming up that is at 60ft. It is in an internal courtyard (8 court yards in total) A cherry picker is out of the question even a Teupen spider lift wont fit due to very limited access. The scaffolding cost is over 18K. After testing the SL2 pole with MR H on a recent job, next to my Omnivac I would consider buying an SL2 for this particular job as I will price it into the job. If it survives the job great if not who cares because it will have paid for its self over and over again. Also the contract will be mine for a long time to come. However Glyn is looking into this for me.
My final comments are
1. The Omnivac is an excellent tool and in its standard form will make you money
2. The Omnivac is all you will need for 99% of jobs and will last you much longer than a carbon fibre pole.
If most of your usage is like below buy an Omnivac

3. At heights where a cherry picker is out of the question an SL2 has its use, but I have only ever come across one job like the one listed above.
4. Commercially if a part breaks or needs replacing I call Glyn and he sends me a new part as its quicker - saves time and messing about. I clean gutters for a living - I leave building guttervacs to the experts.
5. The Upkeeper is fine for domestic work but its no match for an Omnivac - trust me.