Would love to hear pros and cons on 54' & 60' sport yachts

The mans vibrate at under 1200 or so rpms because it is cutting out 1/2 (??) the cylinders for fuel economy. But I don't think it is an issue even at hull speed. Where I notice it is at idle, but for me it is a non issue. When cold they can be smokey but block heaters pretty much eliminate the smoke. I do my thousand hour service every 3 years and the cost is about 14,000. That typically includes all 20 injectors. The parts are expensive 8000 for an intercooler, 1600 for a new raw water pump. When it is rough you are going to roll a lot and be very uncomfortable at hull speed. When fuel was real high I tried the hull speed thing but I think I lasted 30 minutes or so. As a kid I was diagnosed hyperactive, so that may have something to do with that. Not at all trying to discourage you but there may be better choices if you think you are going to run hull speed most of the time. You will be maintaining big hi performance diesel and not needing them. If you go forward with the Viking find out if the torsional couplers have been replaced (25,000) with the silicon ones. Most all will either have it done or will be having it done. You will probably want to paint the boat unless it has been shed kept. I replaced my salon Windows last year, they were leaking. I can't think of the other big issues but ask away and I will try to answer.

Yes, the mans and genny at about 2050 rpms will burn about 60/hr. That is running offshore, in the icw it will be less because of no wake zones and such.

Slingshot and Dennis. Look closely for evidence of leaks around the salon Windows. Mine leaked right above the galley sink. Also the aft stateroom Windows have been subject to leaking. Like I said before the torsional couplers will need to be replaced in my opinion. I would plan on a 1000 hr service if there is no proof that ones has been done within 2 years. Ask the engine surveyor if you have the cast iron oil coolers if not I would have them swapped out. The aluminum ones had a habit of dumping the oil before the alarms would catch it, leading to a catastrophic failure. There are a bunch 30 or so of round recessed lights that on my boat were halogens that I switched to LEDs. That cost about 7000 but the halogens contacts would rust and lose contact and drive you nuts. I had to replace my refrigerator which was a bit of a job. I have had to replace my windlass. The original Simpson Lawrence had a grease fitting that was hidden and I never greased it which lead to failure. Check the deck for areas where the core got wet mine had a spot where the stbd front cleat leaked and had a rotten spot. So sound the deck with a plastic hammer you will be able to hear the difference. That is all I can think of right now but feel free to ask me any questions.

Slingshot as this he boat galati had listed?

I have not seen the boat in person she appeared to be the nicest on the market for the last couple of years. What size mans you got?