Well, even a cheap angle grinder is better than having none. I used my cheap Chinese angle grinder a bunch. I think it was rated at 4 amps (I’m in the US) and I’m not sure how this converts to your European system. But this year I upgraded to a good 8 amp unit and it totally kicks butt.
My old unit had a guard attachment the same as that Ferrex – a screw and a captive nut. I modified it via welding so that it could rotate 360 degrees without the screw stopping it.
And, yes, always use hearing protection with an angle grinder. I even wear it when operating the vacuum cleaner.
Mike