Thanks for the input, Jeff.
I managed to take a demo boat out in variable conditions over the past few days and have found the following:
On the flat, very stable and smooth. I found it to be plenty fast enough, but hey, I’m not at the front end of the field looking to pick up microseconds on the other speedster next to me.  Had the pleasure of 2 great South-Westerlies off Sea Point in Cape Town. These involved a few Km’s of stiff upwind, then some cross wind stuff, and then the downwind run home. Upwind it pushes through the swell well and is quick to get down again after cresting- maybe this is because the cockpit is slightly further forward compared to other skis? I felt comfortable in the messy cross-wind stuff, especially compared to the Mako 6 which I feel tends to ‘roll’ a bit, making me feel unstable.  Downwind I was initially hampered by 2 problems: on the first paddle my left forefoot went totally numb in rather cold Atlantic water, so I couldn’t feel the peddle at all. Result? Sliding to the right across the runs and trying desperately to ‘turn left, turn #@&% left!‘ but without any response from a white and sensation-less forefoot. Problem 2 was that the demo boats peddle/rudder set-up wasn’t perfectly aligned so I had to compensate with more left steerage. However, once this was figured out, I had a blast! It picks up the runs really well and is very maneuverable- for the first time I was able to turn on a run and pick up the next one coming from a different angle. Also, as I mentioned before, because it’s a bit shorter it seems for ‘controllable’ to me.  I haven’t yet tried it getting in and out of the surf, but no doubt that will come because end result of all this… I placed my order today!

Thanks for those replies. I paddle a Mako 6 and Thomas's comments resonate with my experience.

Can someone explain the concepts of 'primary' and 'secondary' stability? How does this translate into what the paddler experiences on the water? Is it better to have more primary or more secondary stability, or is that paddler dependant? Does anyone have examples of which boats display more/less characteristics of each?

I’m looking for some feedback from anyone out there who’s paddling the new Robberg Express regularly. I have seen Rob’s excellent review on the website. I’m an average (in races) but competent paddler; just finished my 3rd summer on the water. Started in an XT and have been paddling a Mako 6 for past year which I don’t feel is quite right for me. Having tried some options, the Robberg feels good for the following reasons: the seat is extremely comfortable, especially as the back of the bucket is cut away and I don’t get the awful chafe on my sacrum that all other seats seem to cause; the seat height is a little higher so gives excellent paddling position (albeit possibly making it a touch more twitchy); and the boat is shorter at 6.15m which feels somehow more ‘controllable’ for a lightweight (76kg) like me. I’m keen to hear how people view the general stability in all conditions, how it rides the runs, and how easy it is to remount.  Thanks!