Ok all you "Surf Slaters", I demoed the 7'x28" last weekend at the Sunny Coast on a 2 foot beach break and earlier on in fairly big fattish Currumbin.
I'm around 87 kg around 5'10, I think from memory and the wrong side of 50. I answered my own question regarding stability compared to my 2015 8'6" wave pro.
IMO I think the Slate was slightly tippier than the 8'6", maybe even leaning towards the 8'2"x28" Wave Pro. Paddling, about 3 strokes per side before changing sides, and I have a big paddle, so not that much different to the 8'6". Getting out over whitewater pretty easy, pops up and over. Paddles onto waves with very little effort.
At Currumbin I had just put my back out, so could only stay out for a couple of waves, but I loved the way it surfed, could pretty well ride off the rear pad without moving my foot. Because of the fuller wave, I was able to get pretty comfy on this board. I found it a bit harder to get it dialled in with the smaller waves up at Coolum,
but only a pretty short session also.
For me, I want to try the 7'6"x29' for a bit more stability, just worried about the 115 litres being too much. Basically I'm just looking for something pretty short to throw around on the wave with a touch more stability than my 2015 8'6" so that I can stand around in lumpy with a touch more comfort.
Hope that all helps