I remember reading a review of the Robber in the late "Small Boat" early in the 1970's but I think that was the flat out racing version, not the Mk III. With that hull shape and a high aspect rig, just don't get caught with too much sail up downwind in a blow because I guess it could get pretty scarey very quickly!
I crewed on one for several years in local club races. It was pretty fast for its length and it was very satisfying to sail. I believe the IIIE version has a higher coachroof than the non-E version but it still was rather low down below.
On one occasion, we went to Cherbourg and Alderney in it with four of us on board. We came back from Alderney having dragged our anchor in Braye harbour - I believe it was a NE gusting 6 at the time (it always seem to be a NE when I am there!). I was surprised at how well the Robber handled in these conditions. At the time I owned a Hurley 22 so I was expecting it to be rather tender but we had no problems at all - mind you the skipper was an excellent sailor. I guess if you capsize in one, it won’t self right readily with its exceptionally wide beam.
I am sure I have seen a report on the Robber somewhere in the past but I can't remember where.
Send me a PM if you want any further information but it was some time ago now.
Our robber (Reefer) has been modified with an extra tall rig and longer boom giving a correspondingly larger main, whilst keeping the same fore triangle.
Do not agree with the comments of Jeremy_W; ref: high aspect rig in a blow downwind. We have found the robber very stable downwind in a blow, even with full main and spinnaker. The trick is to get the crew weight aft and keep the boat under the spinnaker to stop any rolling. The addition of readily adjustable tweakers are a great help her.
Upwind in a blow, the robber is quite fast (especially in flat water), provided that crew weight is kept on the high side and the full main is feathered in the gusts to keep the boat reasonably upright.
Having said that, the biggest drawback of the robber is the light wind performance, where the fat hull shape sticks like a spoon in treacle.