I know what you mean about the hazards of 9" grinders, and the ability to snatch without warning. I've just learnt to hold tight and don't press the tool, just let it do the work, and make a jig to hold the piece firm if cutting small items like block paving. And avoid if at all possible any cutting that involves holding the tool vertical, or not near the ground.
I have a Ryobi grinder from about 10 years ago because it was cheap and I needed it right away. Anyway, it has soft start, a brake, and no latching switch, and needs the safety switch which needs to be held in before the trigger.
I've used this on many concrete cuts (along with some great cheap Aldi and Amazon diamond blades) and it's done really well over the years. The motor does sound rough, and like it will pack in any minute, but has always been like that.
My tip of the day is to also get a toolbox just big enough the hold the grinder and a few blades, and a brush. I've found that these grinders (and blades) are the most unwieldy and awkward things to transport and store. But in a box, no problem.