From my experience, my opinion:
Gas powered + water for dust suppression/ cooling for long and/or many cuts, outdoors only. (Unless you can guarantee air flow/circulation and constantly monitor air quality) Water flow on these is high, you can restrict it a bit but then it gets dusty fast. This is almost like running a hose straight. …
Electric + water for dust suppression/ cooling is most efficient indoors, if you can make a wet mess. Letting it dry before cleanup is generally not the worst idea, but depends heavily on the surroundings. If it’s a finished basement with tiles and all, you want to clean it up immediately while still wet. Otherwise you end up cleaning multiple times and probably with a suitable solvent to get the then present “cement haze” off. I’d recommend using an appropriate tool with “GFCI” build into cord only. Saw spins slower, less water, less mess/ easier to control.
In both instances, water sprays out the front and rear of the saw, it’s also not dust free when starting a cut. So cover everything, that can’t be moved out, in line with the cuts you need to make. Everything fairly close by should be covered for dust protection as well.
Electric + dust extraction is less mess, if you have a tool and a dust extractor that are both fit for the purpose. Will still spill dust while plunging/starting and exiting a cut. Installation of dust wall(s), dust door(s), (…) highly recommended. A separator will take quite a bit of load/stress off the dust extractor and is a good idea. However, make sure you still get enough suction at the dust shroud/ tool. Otherwise it’s a tradeoff not worth it.
If you start seeing excessive amounts of dust at times other than starting or exiting a cut, something is wrong. Stop & check. Dust shroud, hose and/or connectors like to get blocked.
If you go the angle grinder, diamond blade + dust shroud route, get a fully enclosed dust shroud. Not one of the metal ones that, while having a connector for a dust extractor, are still half open.
Not worth it:
https://www.boschtools.com/us/en/products/19dc-9-2602025285
Worth it:
https://www.boschtools.com/us/en/products/ga50dc-1600A003DR
Both just for reference, both exist for the large angle grinders as well. (At least around here …)
Kind regards,
Olli