We put a spinaker on my Getaway last year. It was from a H16 and we installed a snuffer. For racing it seems a little slow. It is an older spinaker and I was told 2ft were cut off it. We could not mount the upper pulley quite as far up the mast as on the H16 (mast was a little thin up there). The H16 mast was a little taller than mine.
But just to go out sailing I love it having the spinaker. It really makes the boat a lot more fun when the wind is low. Especially if you have spouse and kids on board. The down wind sail is very smooth with the spinaker up. People on the beach love all the colour (which is another thing people like about the Getaway - the colourful sails). I also use it as a really big jib when the wind is really low. It just means I can go out when the wind is so low - I normally would give up. I have to drive an hour to the marina - so being able to go out - even when the wind is low - means a lot to me.
I sail mostly alone (with other boats prefered) and I was very impressed how I could manage all three sails. You have to love how simple it is to operate this catamaran.

has any one since this post actually tried one or bought one? looking at getting one but want to see what others think of it first