I started on the same road as you, but took another deviation : I bought the kosmosima to wait while they finally finish their z twist optional kit.
Will resell it later on or keep it as a spare piece.
I will be honest, the gunfighter is .. well imho, it's way better than kosmosima in design and options but .. BUT .. kosmosima is still on the top 5 best joygrip avaiable around.
If you are willing to spend the buck for another full joystick from another brand, maybe give the kosmosima pro it's chance, it have the z grip included, work perfectly in star citizen, robust, well designed and so on .. a fuckin' bunch of button to smash (couldn't configure them all at the moment .. with a dual clic on the base button + hats, I get like .. around 40 buttons to press

).
Up to you, I'm set to wait the twist adapter for quite some time now (yes I still perfectly favor the Gunfighter).
And .. yes I ressent too the long long long long tooooo long coming of the twist adapter, as it was promised 1 year 1/2 ago at least by now .. but I assume there are reasons for this long delay .. especialy for an adapter that is not initialy solidified in the grip body.
There must be some kind of reliability problems to fix before releasing a good product to us and they just released the kosmosima so .. at least we know it's on it's way

.