If I'm building a cabinet for someone like you who wants the appearance of floating but with a traditional toe kick height, I'll simply make the toe kick deeper.

How deep can depend on the size of the room. But if for example it's recessed 10" to 12", it gives the appearance of a floating unit as it's recessed enough to not be seen with normal sight lines, and by not being a true floater (full depth but only 5" high) it's not dust-bunny haven under there.

A 7" or 8" toe kick on a true floater is fine.

Not sure of the overall look you're going after, but lighting under a floater can be a nice detail too. Either as accent lighting or as a night light.

Because there was no other storage on our bathroom, I had to maximize the size of the vanity. So we left 6". Also added lighting underneath it.
The more space you leave, the more the 'floating' effect.

In another bathroom we will not have a vanity at all. Just a slab of floating wood counter.

Mongoct, that's a good idea to just do a deeply recessed toekick to simplify cleaning if we stay with just 5" below the vanity. The room the vanity will be in is 6' x 6' (the shower and toilet area is separated by a pocket door). The look I am going for is clean and modern, but still tranquil and spa like. I will consider the under-cabinet lighting.

Pharoah, thank you for posting that picture of your gorgeous vanity. I love your wood grain. It is very helpful to see pictures and know the measurements. I am afraid I will not get the look I am going for with less than 6".

I can probably reduce my drawer section to 28" to get 7" below. I was originally planning on having 5" toekick drawers to store the scale, extra boxes of toothpaste and lens solution, etc., so I am really reducing my storage a bit to get a look if I go this way. Form vs. function is a constant battle. I am doing a wall hung toilet in the adjoining room, but that gives me both form and function as it will be easier to clean around and the in-wall tank frees up floor space in a not-large room.

Like the idea of the deeper toe kick. I don't want to have to get on my hands and knees and dust under a floating vanity 5" above the floor.

I love the look of this floating vanity. the problem is i just had my electrician replace our grubby old baseboard heater with a kickspace heater in our existing vanity. we were planning to replace the vanity eventually and i love the fliating look. im wondering if i installed a deep recessed toe kick, would it be safe for the kickspace heater to be installed so far under the cabinet? i cant seem to find any information on that.