I have the zpacks groundcloth, its not a perfect solution, its not even close. It helps some. But the edge of the ground cloth can still be pushed into the mesh, which funnels water right into it. It is also a bit too wide and the ends tend to lay flat basically anyway, the geometry of the support points wont stretch it tight width-wise.
On a slope, it is especially bad because i keep sliding downhill until it happens. Cant always find a perfectly flat spot in the mountains, especially in a hurry.
I was really surprised at the amount of very fine splash that comes thru the mesh door even with the beak in heavy rain, Dropping the pole height helps. My first night of thunderstorms at 5000' on the AT, I had to put pack, raingear, and sleeping pad across this side to stay totally dry, but I did and slept good. I just let my pack get wet.
One of my taped side tie-outs leaked as well, micro-wrinkle in the patch, steady stream of water down the roof of the tent, but no drips , had to seal that , as well as the tie points for groundsheet, they will wick water in. Cant count on water dripping outside the groundsheet, too easy for that setup to mess up.