What's the suction on these Fisher & Paykel hoods like?

Yes there is a quiet alternative - a flush mounted ceiling extract. You can position the motors up to 8m away from the extract unit however really need roof space to do this. They are excellent though and you don't have a dominating stainless hood in your kitchen
https://ikoncommercial.co.nz/shop/ikon-rangehoods/ik20-ceiling-unit-white/

Equal to the issue of suction quality, I rate fan noise as a serious concern. you can't tell what the level of noise is going to be by testing it in the shop. At the moment my exhaust fan is so noisy I can't bear to have it on. They told me in the shop it was the quietest one they had. Is there any rangehood in the universe that is whisper quiet?

suction or better said, extraction capacity my depend on the power of the blower (how many cfm´s it has) and the size the room where the hood is located. Another important issue is what kind of cooktop you will have. Hoods for Electric or induction cooktops work usually fine with a 600 cfm blower. The formula says that the best extractor has to be able to change the air of the room at least 10 times.

Thank you HR

From what I've seen they are as good as any other brand.