I know the disadvantages.
What are the benefits? I've just bought one mainly because I could get a 100% carbon mast + sail to suit for a price to suit my budget. It will be my lightwind sail so there shouldn't be too much chop - 5 - 18kts.
More stable foil means the centre of effort moves less and therefore you don't have to fight the rig as much. Also maintains shape in lulls better.
More grunt 
Non-cammed V cammed is like comparing a 4 pot to a V8.
Plus what Paddy said...greater stability = wider wind range. Typically you can hold down much larger cammed sails in the same strength breeze than non-cammed.
That also means more speed 
Cammed sails need to be powered up. IMHO in 5knts you may be better off with Rotational sail as a cammedone will feel heavy.
Cammed sails are loads more stable so yon can use bigger sizes in higher winds. for eg
In 25knts the ideal non cammed sail size would be in the 4.5-5.5m range while a 6-7.5m cammed sail would be fine
Perhaps someone can explain something to me that never made sense.
When it is claimed that because a cammed sail holds it's shape it is therefore better in a lull, how can the sail holding it's shape be of any benefit if there is no wind to propel you?
^ maybe because of the apparent wind?? (during the lull if you are still moving forward, there is some air which flows over the aeroplane wing foil shape, generating lift, which helps propel you along?)
You'll find the cam sail has a more locked in feel. The draft is very stable so can use a larger sail therefore producing more power and drive. The non cam sail has a limited top end while the cam sail seems to have another gear up it's sleeve. Saying all that, I prefer non cam sails when mucking around in the ocean but cam sails are by far the best in protected waters for maximum speed and comfort.
also, size does matter
over 7-oh I prefer cambered sails
under that size - non
and as stated - in bigger steadier winds you don't need the cams as much
for my size/weight my 6.3 is used in 30 to 50 kph ie about 20 knots
those winds may be gusty, but they are also strong with few lulls - typically
my pros for cambered sails ?
works great on longboard as well
can rig it with the leech fairly tight and big pocket for grunt n pull
also, as mentioned - range
my 8-oh cambered has more range than my 8.5 RAF did
and slides through lulls - especially on the longboard
btw lull does NOT mean NO wind :-)
although I used to be able to duck gybe in the 90's and I was watching a video on how to do them last night and thaought maybe....
maybe not 
If there is any wind it should propel a cammed or noncammed sail equally IMO, so I don't really understand the claim that that the cammed sail helps you thru the lulls.
Perhaps when a sail is flat and a sudden gust fills it up the sudden surge of power can overpower you?
Even when it's glassy there's still air movement, which is after all, what wind is. It's as close as you'll ever get to perpetual motion. However, whilst that's correct, you certainly can have too little air movement to be of any use to a windsurfer. Having raced sailing dinghies for many years, no matter how glassy the water is you can still make headway.
From what I read cammed sails sound like a good idea for the newer sailors wanting bigger sails as well.
@ beagle - Do a web search on how an aircraft wing works, this will explain the concept. The shape of the sail crates a difference in pressure between one side and the other so the the sail wil move to the area of lower pressure.
I believe that we owe the design to the ancient Egyptians and the feluca sail.
An aircraft wing for low speeds has a very thick, forward profile.
Yet to sail upwind we tighten the outhaul, thus reducing the profile.
Who is screwed up here, the windsurfer or the aircraft designer?
