What the upgrade actually buys you
The functional difference is water. A deluxe flushing unit carries its own fresh-water supply, so the bowl flushes with a foot pump and there is a working sink inside the same enclosure. Guests wash their hands where they used the restroom, which is the single thing people notice most at a wedding or a customer-facing event.
The rest of the upgrade is fit and finish: a mirror, a shelf that will actually hold a purse, a coat hook, interior lighting on most models, and a larger floor area so the door is not brushing your shoulder. It is a noticeably better experience at a fraction of what a restroom trailer costs.
When a deluxe unit is the right call — and when it is not
Choose deluxe when the people using it are guests rather than crew, when the event runs long enough that comfort matters, or when a site office is going to be someone's daily restroom for months. Choose a restroom trailer instead when you want climate control, multiple stalls in one footprint, running-water vanities and a genuine indoor feel.
Choose standard units when the users are a working crew and the budget is better spent on having enough units rather than nicer ones. A well-serviced standard unit ten steps away beats a deluxe unit across the site every time.
Servicing a water-carrying unit
Because the flush recirculates a finite reservoir, a deluxe unit has a real service ceiling that a standard unit does not. On a busy multi-day event we plan servicing around expected traffic rather than a default weekly route, and for high-volume weekends we will often recommend more frequent visits or an extra unit so no single unit runs its water down.