Thank you all for you inputs :-)
From your answers, my only conclusion is: it's not such a bad idea to get one :-)
And yes, my EQ6 can still manage it.
At first, I was thinking of mounting my 10" Newtonian on it but 13 kg+ does not seem to be easy to carry (my biggest concern was and still is that dovetail flange.. maybe it is OK for such a weight, but I was always afraid to try it, despite some people saying it should be right..
So, GSO 8" RC was just decided