I wouldn't call myself a great expert. I tend to cycle to Scout camps, which hardly makes me a long-distance tourist.
However, I can get a 2- or 3-person tent, a sleeping bag, a sleeping mat and sundry related items (pillow, sheet bag, etc.) in one pannier. Clothes in the other. Bike-related stuff in the rack pack, which tends not to be full. Front bags have stuff I need on Scout camps but wouldn't take otherwise (various spare shoes, paperwork and files, and so on). On the other hand, I don't take a stove because I'm not cooking for myself. I rarely use the bar bag shown, but can if I need the space.
Handling is a bit heavy and slow to respond, but otherwise OK.
Traditional advice is to pack low for stability, so I'd try to keep stuff off the top of the rack. Distributing weight front and back helps stability too, though if you can avoid front panniers and without overloading the rear, that's no bad thing.