Share your experience from Hartley to Black dog cat. what has been the  best riding hull you have been in. I would have to say a 6 mtr Haines Hunter was my best experience; had a 200 hp on it and we were doing 50mph thru chop, this was a log time ago but it still sticks with me.

I've had some pretty smooth trips on the Inter-Islander in 30-40 knots?!...

I think so many variables in such a general question
Once one gets over 17 or 18' makes a huge difference....
Then get over 6.1m and again another huge step in change
Then there is fiberglass over Ally
Then throw in a well powered hull over a min powered
And of course at the end of the day, the skills of the skipper at the helm... and consideration of certain female body parts.

Sry m8.. I didnt mean my post to sound directed at u....
Real life in my experience with ladies worked like this
A male 'mentor' sometime back commented to me about "consideration to be given to certain female body parts"  and choppy waters wakes etc.
I took , like everything else he has told me on board....
But in the early days with wife on board "She's stable and comfortable in a chop at 45mph and cruises nicely at aprox 25-27mph. Then the missus tells me off"
things like falling off the plane because missus uses one full name stuff..
With a little experimenting with trim , speed in different chops etc with the guys, and a little co operation with that experimenting, with just the missus and I ... a lot turned out , not "body parts" but the rough 'rally driving surface and  min plaining speed....
The wife now understands dropping off plain, climbing up and down the chop, or tapping the peaks, maintaining a little bumpy ride, balancing with body parts, along with more suitable clothing in choppy conditions when returning home.
So now a 8 min cruise trip across the channel on flat water, to a 20 or 25 min in a westerly, is now more like 12 to just under 20 mins...with a little consideration and give and take on both sides
And day ends on a far happier note, with wife keen to get out on the next weekend weather window.

Your post and my comment where meant to be independent  unrelated comments

~9m AMF.  8mm alloy plate hull and structure, nice deep vee, wideish chines.  Not mine of course.

Punching into a fresh Norwest the limitation on speed was getting the spray off the windscreen fast enough.

I think a lot of the glass vs alloy difference is about weight.  Generally a glass boat will weigh a lot more than an alloy boat of similar size and design.

When you get into commercial alloy boats with heavier hull plates and top sides and more framing, the weights become comparable and so do the rides.  This even applies to small commercial boats around 5 - 6m.

My dads 8m cat, best ride by far. The faster you go the better the ride, no banging or crashing, like riding on a cushion of air.

Smoother hull could be a factor - as if the hull cuts into the water more, it wont bang into it as much. I hadn't though of that possibility.My Frewza 4.1m aluminium pontoon boat, is rather hard riding in a chop; so I throttle back  - generally, do 15 knots in a 10knot wind, and roughly 10 knots in 15knot wind - varied by other factors (sea direction, current).  I look with envy at the fibre glass boats passing me. As a rough rule of thumb, I reckon fibreglass boats of similar size to mine, do about 5 knots faster.

Multi hulls are complicated.

This is my own personal opinion and experiences. Sorry if I offend anyone.

Best
Fibreglass- Haines Hunter SS700

Pontoon -750 Senator Was fishing on one in the first ever Kings of the Coromandel, if you fished the first one you will know how **** the weather was.

Non pontoon- 5.5m Lazercraft, been to the Kings on one!!
AMF prosport 5.5m That thing was awesome.

My ex boat a 560 Senator HT. This was an amazing boat for the size of it.

Bad,

Stabicraft 589, I call these the chiropractor boat.
Surtees- 6.1. spent alot of time in one. Just not for me.