There are a whole lot . . .
You're Roboclean is a really nice looking machine AND you are the first person that I have encountered that owns one. I'm much impressed. Anyway . . .
I'm probably missing some but the brands that come to mind are Delphin, Hyla, Big Power (no separator), Rotelli, Aroma (if they're still in manufacture), the Rothco which may be trying to work in bags, the Ocean Blue (a barely masked Rainbow clone). Euro Pro made one, also sans separator, years ago. It strongly resembled what we call Hyla now. There's a European machine -- the brand is Poulti -- but I'm not sure if they are sold here though I believe its vapor steam cleaners are.
Not to forget, there is also the Gaya (or something like that) that employs suction and vapor steam separately or together for vacuuming and floor/above-the-floor cleaning.) I remember inquiring about them a good while back but learned that a shortcoming was that the 120 voltage version for the U.S. did not perform as well as the European counterpart that was intended to operate on higher current.
If you're thinking bagless, water-type vacs are a not bad alternative in that clean up means not having to deal with dry, airborne dust in the process of emptying the machine. When I was done working, I'd take the water pan straight to the toilet and flush away the contents. Nonetheless, the water pan would need a decent wash and rinse at the kitchen sink. And, of course, the separator did too.
There you have the fly in the ointment as far as water-type vacs go. They can't be just pulled out of the closet plugged in and used, then put away. They must be assembled, filled properly for use, then disassembled and properly stored if you want to protect a usually expensive investment. Rexair/Rainbow always insisted its motor unit not be stored on the water pan -- even though empty (bad for the life of the seals). Many makers of other machines call for the same in their user manuals.
Another hitch is that since the filtering medium is water you have to tolerate extra weight. Going for the option of a larger water pan to allow extended cleaning time means even more weight. Speaking of filtering medium, its suggested that you change the water in the machine after every 15 to 20 minutes of use. (That compensates for not only the amount of stuff you pick up but I think a certain amount of evaporation too.
All that said, by type, these vacuums are an acquired taste and not a lot of people learn to live with them -- especially those purchasing them as a sole vacuum.
I have always loved the pure science of Rexair and Rainbow and thus have owned a few. The suction was good enough though I could have lived without Rainbow's straight-suction rug tool with the louvers on top. The other nozzles -- the original vertically pivoting one and the two that used the knurled bolts you had to loosen and tighten to change the brush height gave me more of a feeling I was cleaning.
I very much liked the Eureka-cloned power nozzle that came with my D2 but have never been much impressed with the it followers through the years.
