Hi,
I am after a sail to match my Fanatic Falcon 133 litre board (79cm wide) for light winds of 12-15 knots.
I was thinking of getting a 8.6m blade loft, comes with matching loft 490 rdm for this board as a lightwind rig. Option 2 is a Loft Switchblade 8.5m, comes with a matching loft SDM mast.
These are the 2 rigs I have to decide between. I wont have the oppurtunity to pretry any of this gear, so have to decide without trying 1st 
My specs are 6ft tall, 95 kgs. Sailing style= maxed out, aggressive, like to be challenged.
From what ive read so far heavier sailors tend to use sdm more, saying that rdm's in 490+ length tend to feel too springy/spongy for there heavier weight.
Dont know how much of this is actually true or not but it does make sense.
So basically would like some input from you heavier sailors (95kgs+) out there
as to what would suit me better 
Cheers guys 
Some of the racers up here use RDMs on Loft 8.6s. I'm sure if they thought SDM was an advantage they'd use them instead. Hopefully they'll provide their opinions for you. Lofts are also cut for constant curve masts so you stand a chance of finding a few different brands of mast that will work with them.
Pretty sure you didn't answer the question, DP asked opinions on two Loft sails, not sure he asked for opinions on someone trying to sell him another brand.
DP do you use RDMs now?
From my experience it's always ideal to have a sail that matches the same brands mast, option 1 would be my pic.
Select to expand quote
Forget Loft get a Hot Sails Maui 8.8m GPS with a match Hot Sails Maui RDM mast. It is better priced (25% off at the moment) and better built than Loft.
Sounds good, however I just want to stick with the 1 brand now as I use loft for most of my sailing nowadays.
For a lightwind setup I think SDM will be superior. They tend to be stiffer in the lower section, around the boom area which generally lets the sail set a bit fuller in the lower half.
In theory if the 2 masts, RDM and SDM have the same bend curve then there should be little difference, but my experience with KA Koncepts in the larger sizes has been that the SDM gives a marginally more powerful setup.
I think Monty may have a bit of a discussion about this on the Loft website, could be worth a look there.
Ok ive decided to go with the 8.6m blade and 490 rdm combo.
I think the pros outweigh the cons on this topic after reading everyones input.
Rdm 's also rotate a lot smoother imo than sdm, so if ya love ya gybes then its a no brainer for me :P
Valid point about the extra durability of an RDM Vando. I am running RDM's on my smaller Koncepts ( the speed sizes) as I am much more likely to have a big off speed sailing than lightwind cruising. Like the Blade you can use either RDM or SDM on the Koncepts just by changing the cams.
I know I've been told before but i still keep getting them mixed up..SDM = standard diameter? RDM = skinny? 
I can give you my experiences from some recent experimenting I have done with a HSM GPS demo sail. I'm around 92kg and I like to rig big so i can stay powered in gusty conditions.
Rigging the GPS with the reccommended skinny (RDM).
The sail felt springy and soft and seemed to twist off better (but I havent had a lot of time and tuning).
The whole skinny thing is new to me, but what I liked is that the softer sail had a lot less shock and impact transmitted through rig, board and my knees. This meant that I could charge harder through chop, not tire as quick and probably end up being faster.
Rigging the same sail with an NP SDM there was a noticeable increase in the the belly below the boom and you could really feel the extra power. I needed more DH to improve the twist, which didn't feel as good. I felt the bumps more.
I would encourage you to give the skinny option a try, you may like it for the sort of sailing you do.
The Loft pro riders/while testing new sails found there was no difference in top speed between the 2 mast types, the SDM masts accelerated quicker than the RDM, RDM's however were less tiring and easy to close down in rougher conditions + alot more durable, only downside is that they are slightly heavier than equivalent SDM mast.
I'm paying close attention to this discussion as I might look into a 8.5-ish in the future and I'm also 95kg-ish. I've been lead to believe the future was in RDM and SDM will eventually be phased out? Because of this I've only looked at sails and rigs to suit RDM...have I been mislead?
Just to further complicate the issue, sorry.
I use a 430 powerex rdm on my loft blades 7m 2011, 6.3m 2012 and really like the way they work.
I recently put a powerex 460 100% rdm in the 7m (4cm over length) and it really changed the feel to a more powerful, draught further forward sail and feels great for lighter winds.
So it is not simply rdm vs sdm argument
As a 75kg sailor though I definitely prefer rdm.
