Lazzara viewpoints

There are thousands of ways to built a boat and some have done a good job with all of them and others a poor job with the best of methods. You're wise in not accepting a universal rejection of balsa cores but finding out from those with experience about Lazzara. Then, like any boat, your survey is key.

Well, it can't be such a bad technique, considering that also Azimut started moulding their hulls with balsa cores, more decades ago than I can remember.
Though they moved on from that afterwards, already 15+ years ago...

For myself, when I downgraded to plastic after getting a bit tired of maintaining a timber boat, quite simply I did not even consider anything built in other than solid GRP, at least up to the w/line.
Which BTW I believe is true also of your Hatt, isn't it?
But each to their own, of course.

My understanding is that avoiding to drill new holes could not be enough.

Over time, hull flexing can create air "bubbles" inside the core.
In turn, this allows the formation of internal moisture, which is what eventually can root the balsa.
And this is particularly dangerous because you have no way to spot if and where this is happening inside the hull - aside from regularly make extensive moisture readings along the whole hull surface, after leaving the boat to dry on the hard for some time.
Something I never heard anyone doing, possibly aside from when commissioning a purchase survey.

Besides, it's a sort of self-developing process: once any air inside the core begins developing moisture and attack the wood, the void areas tend to progressively extend, making moisture develop faster, and so on.

I'm not suggesting the OP to steer clear from Lazzara boats particularly, mind.
But for myself, balsa cored bottom indeed is a deal killer per se, regardless of the builder.

I’ve run a number of Lazzaras.

I’ve found them well build with good attention to detail. With the on board systems such as A/C, heads, water pumps, etc., etc. installed correctly, as well as with thought given to serviceability.

And they have about the best owners manual I’ve ever seen.

Any opinion on the quad IPS powered LSX 75 re build quality, reliability and seakeeping ability ? There seems to be a fair amount of variation on the earlier hulls.

I know absolutely nothing of that boat, but IPS is one of those things that I call "OMDB" (over my dead body).
So, you can guess how much I'd love to deal with four of them, regardless of how good the boat can be...

I sea trialed two 75's. Both early model boats and relatively new, under 100 hours. I don't recall any vibration, but keep in mind when you have 4 drives and 8 props (each independently operated), there will be thrust interaction. Where are you getting this information from?

YF mod AMG has seen many installations of IPS drives into the Delta line of boats he designed. Similar size boats but built in carbon so if there is a vibration issue, it will be amplified. Let's wait to hear about his experience.

My previous comment wasn't referred to vibrations - or any other defects, for that matter.
It's the very expensive IPS maintenance, both scheduled and unpredicted, that make me prefer to steer clear from them.
For instance, even a thin floating line that shafts would eat for breakfast, with IPS can damage the shaft seal, emulsionating oil and requiring a boat lift PDQ to avoid further damages.
I've seen invoices for IPS repairs which would have been funny, if they weren't real.
I do have also reserves on how some IPS-powered boats behave, but these are vessel-specific.
And as I said, I can't speak for the model Chris229 is interested in, so I don't.

"Variations" or vibration?

I happen to like IPS and feel they have a definite place in the industry, but four of them on a 75' in not that place.

Before Lazzara closed shop, Dick Lazzara refitted several 75’s by replacing the four 600 IPS with two 1200 IPS. Looked like a nice refit. I have had four boats with IPS and have had no problem and love them. Only recommendation is to get a boat designed for IPS not one that has an option for conventional drives. I had a Sunseeker built with IPS drives as an option. It had jack-shafts connecting the motor to the drives and got none of the extra space IPS gives

I agree with all this and add that they made a name for themselves as having shallow draft and being efficient. The big caveat is they never learned from or fixed the key things they were not good at. Namely ceiling panels always falling down, wall fabric/material seperating from the foam it was attached to so walls looked like shower curtains, and poor gelcoat that never retained a real shine. Even on the last boats they used the same materials.

IPS drives are known for having a lot less vibration than shafts, so I wouldn't worry about vibration as far as that goes. However the 75' LSX is REALLY hard on drives and they all generally have to be rebuilt every 2-3 years at a cost of $30k a pop or so........I sure as heck wouldn't want to maintain 4 engines and drives. That being said, the LSX has a great layout and a ton of room inside.

We chose traditional shafts on Sunseeker simply for the reasons you point out that they weren't designed for IPS and didn't take advantage of them.