I have only been doing this for 5 years but have gone through now three Dyson cordless vacuums. It's almost always a battery issue... I seem to have a love-hate relationship with them. I would not recommend them at least as a long-term investment.
I am so glad you asked this question because I know I will likely need another one soon.
I stand by the Dyson and usually grab whatever the latest model is +The Allstate insurance option. Their batteries are horrendous but with heavy use you're almost guaranteed to get a replacement or a new battery over the course of a few years.
@Inna22. My cleaners use a backpack corded one (no idea of brand). If I have to clean I use either the Bosch which stays at one of the listings (corded with bag, hardly used). Or I bring my Miele Pet with Turbo boost (corded bagless). Works great on cat hair or long hair dogs.
Most of the time I'm getting rid of the sand though 😉