Well, I finally took a big, deep breath and bought a Sony a7riv. So far I'm quite impressed, after finding where in the menu system to customise the control buttons. However - not so impressed with Sony's QC on the hotshoe. I initially thought that Sony had disabled use of non-Sony flashes on the camera. I couldn't get a flash or radio trigger to fire in the shoe, even in fully manual mode. The P-C socket worked. So that ruled out a faulty synch circuit. Then I poked about on the camera with a DMM in continuity check mode. The lens mount and metal strap lugs were clearly electrically connected, but the metal mount of the hotshoe? Nothing! Not even a high resistance reading. Long story short. It appears that paint overspray, or some other coating, was insulating the hotshoe where it should have made 'ground' contact with a flash or trigger. A quick scrape with a craft knife blade removed the paint/coating and I was then able to use a speedlight or radio trigger in the hotshoe. But really, I shouldn't have had to do that. So if you buy a Sony Alpha that doesn't fire a flash; have a good look at the contact area of the hotshoe before sending it for repair. And Sony: If you're reading. Pay more attention to detail in future. It might save you a few needless returns or warranty repair claims!