even if I had ridden this board my opinion of it would probably be completely different to yours
The only comments I have to make about the board are in general terms:
The advert states the 5'9" board has reduced volume & its width 45cms -17 x 3/4": I would suggest to you that more volume - more width & thickness - is gonna work better for your 90kgs
I'm 75kgs, my most frequently ridden boards dimensions; 6'2" x thickness of 2.1/2", x width of 18.1/2", x tail width of 14.1/4"-
I have a 5'11" x 18" x 2.1/4" x 14" that I ride when the conditions are 25-35kts, double-overhead waves, choppy sea-state - but it doesn't go so well in less than head-high waves & only 15-20kts. The RRd 5'9" sounds even smaller than my 5'11".
For me, the whole reason for stepping off a mutant kiteboard or a tt kiteboard or a 5ft kitesurfboardreplica & onto a surfboard is to gain true surfing performance on the wave ( & to reduce the kitehaulingbuttwigglingslippysliding).
If you take away from a surfboards volume & width you are reducing the advantages a surfboard has to offer over no-volume "kiteboards"
Riding a 6'2"x 18.1/2 x 2.1/2" surfboard allows me to ride waves with or without kite-pull, you can slow down to match the waves speed, ride vertcally without bogging-rail or sinking & engage with the breaking curl of the wave ( & when the wind drops, you just paddle back out )
Try to beg, borrow or salvage some boards, try before you buy - get out there & ride some waves.
There is no one-board solution to suit all the conditions that you will encounter & if you get seriously into the pursuit of waves you will end up with a variety of different shapes designed to suit your style & the waves you are riding
You could just buy yourself an old 2nd-hand 6'5"polyester surfboard for $200 - ride it strapless - you'll have alot more skills for strapped riding if you start out like that.
Seano thanks for the hints!
Another guy i know is 85 kg and he rides a 5'6'' which is the same size his brother has who is 70 kg!
These boards are custom and the guy who made them changed something in the volume. A bit more thick i guess!
I'll try some surfboards if i have the opportunity.
P.S. I have a fish tail 6'6'' from airush 2001 model with that help to get into waveriding?