Maybe it's like the post on riding big stuff. Only having a wave sail is a good excuse for not going REALLY fast!
Maybe they're a bit cheaper?
Built a bit stronger?
And if there's a chance you might get in the surf-------------

i use both.
0-25 knots race gear all the way. which is 90% of my sailing
race for 7.5m and up

20-30 knots and i like to bump and jump, go in the surf etc.
for me. wave gear 6.4m and down

wave sails are,

cheaper, 30-50% cheaper
easier to rig,
almost bullet proof,
loads of fun and light,
and not that slow.

when you are talking 30knts+ southerly at Botany Bay I doubt you will get alot more speed on a race sail combined with a slalom board. Maybe if you are Bjorn Dunkerbeck.

With the chop you get there you will be spending most of your time trying to keep the board on the water.

Also found that Neil Pryde wave sails (especially the Search range) have enough power to easily keep up with a race sail in 30knots.+ combined with chop.

On the other hand wouldn't mind trying a T1 65 with a 5.8 NP RS6 in 30knts. . I am sure that would be a fast combo.

It aint the sail - it be the board.
That thing is a lethal weapon Hardy - I miss it..!

AB....