Its been a couple of months since getting the RRD Wave Cult Quad fin, and I have recently decided to take the brave decision as using it as my one board (at least for long journeys and travelling with kids).  So with car space at a premium I made the seemingly bizarre decision to pack this 92 ltr board (AKA the 'big board'). I hate being underpowered probably more than anything, so having a slightly bigger board seemed like a sensible option. Now the law of averages would suggest that as soon as you agree to leaving the other boards behind, you can bet that they would be what you actually need in your time away. I of course always try to remind myself of this , but its of little solice as Tarifa is a very windy city in August !
Hence you could have brought any board and it would have been right on certain days.
Winds of 40knots one day, then dropping down to single digits the next means you have plenty of down time, but it also can potentially mean limited time for sailing.
In our own circumstances, this trip was a family holiday not a windsurf trip, but that said I still had clearance for the kit.
So turning up at the beach to sail in 18 knots one day and then 30 the next, has been a real joy considering its been on one board. Speed and control has been the key, and even when conditions were light it was still very throw around and you can really slide the fins out too in an attempt to freestyle. I even scored some rare summer wave conditions and the board of course comes alive in this. Essentially the board never seemed to overpower even when my sail did, and the edge of quads over a single fin is far too apparent to be ignored. In Tarifa I noticed a lot of thrusters coming through which seems to be a Naish/Mistral thing, and they no doubt work. However  nothing is quite like a quad, as they still seem to retain the looseness of a twin fin, as opposed to a thruster which seems to be more like a single fin. If you are in any way tempted by a Quad, then I suggest you just buy one. I certainly have been amazed by the RRD wave cult.