After a year on the HG I76, I purchased the PFI 730 lower and W103 carbon mast. The mast was coming a couple weeks after the lower, so I got the Phantasm fuse to HG mast adapter so I could test the components individually. I honestly never had any complaints with the stiffness of the HG mast, but its also the only system I've ever ridden, so no comparison for reference.
PF1730 and HG 90cm aluminun mast.
The PFI 730 still has the wide speed range, easy launch of the 76 but feels more "floaty" and not the "locked in" feeling of the 76. Make sense with lower surface area. Moved the foil mast further forward as the sail base pressure would drive the nose down quicker. Once I got the pitch balance sorted, control was easier. In lighter upwind, the 76 felt like it would point higher but get hard to control lift when overpowered. The 730 felt better in those situations. Going off the wind is where things interasting. The 730 "feels" faster but without a doubt has a ton more glide than the 76 without the tendency to rise as speeds increase.
On the 76 I stay on the gas as much as possible throgh the jibe. Stay switchfoot until the cambers are rotated and powered up before the foot switch. The 730 has so much glide in high speed jibe, I'm in the straps headed the other direction before rotating the cambers and powering up.
Sheeting in and bearing off downwind on the 730 was fast, but sketchy to control in like powered up broad reach going for speed.
PFI730 with W103 carbon mast
Ok, this is an absolute mind blower in control !!.
This changes everything. This platform is rock solid. Like standing on a sidewalk compared to the 90 aluminum mast. Everything is so much easier in wigh wind/wave situations. The extra length and stiffness charging upwind through deep chop requires less effort, and easier to keep the nose down. Off the wind is an absolute blast. No over foiling at high speeds. Way easier to control than the HG. Where I used to "I'm gonna wait for that insane puff pass by before I bear off", now I sheet in hard and send it !.
Bottom line..
Both kits (Hoverglide and Phantasm) work very well together as designed, but to get the full potential of the Phantasm, the new Mast is a must IMO.