We just took our first cruise in Haven, not sailing with NCL in 20 years, we mostly sailed with Celebrity ( over 50 cruises in total). We sailed on Gateway, 9 days Caribbean. We absolutely had no issues or complaints in regards of " Haven" experience and product.
Our suite was specious with jacuzzi tub in the room, plenty of closet space. Our butler was very accommodating, although we didn't have a lot of requests, just coffee with almond croissants and muffins in the morning and real cream for coffee, not non dairy little things they had . She was keep asking if anything we need or want. Suite was cleaned every day. In regards of Haven restaurant - fantastic service overall, minor issues, not worth talking about. Never had problem to substitute of some side dishes. Food was very good, and I am very picky about it. Overall great experience. I thought it was worth $$$$. It worked great for us to have own space and not to be in the middle of the crowds. We have some health issues to consider. We didn't like NCL perks as much as Celebrity. Internet perk is useless, even we paid to upgrade, it was spotty and slow. Ship overall felt very crowded and not very well designed. We will go in Haven again, but it will have to be for a right itinerary and price.