As long as you've got a decent vac, it is not that important what model it is.
Something I do with all my customers, but is especially useful if you find yourself in an uncomfortable position if Madam has a similar model is this. Firstly acknowledge that they are great machines, but like all vacs, it's vital to keep them in tip top condition. Show them things like why it's important to change a bag when it's only about 2/3 full. If it's bagless, don't let the dirt build up as it increases the soiling rate of the filters. Show them how to clean the filters and how often. Rinse them well with fresh water to remove the "clean invisible" detergent residue soil. Tell them that they must be totally dry before they're re-fitted as the air goes through them to cool the electric motot, and damp filters + electric motor= BANG

Now show them how to vac the carpet properly. They need to do this just once a week, the rest of the time they can do their normal quick "litter pickup". By now, they will be pleased that you have shown them how they can keep their carpet looking pristine between your visits, and they will be delighted that they had the wisdom to buy a vacuum cleaner that's good enough for the professionals

By the way, I run a couple of Victor Gold widetrack models. They're fine machines, but next time it will be Sebo all the way.
Safe and happy cleaning

Ken