I'm pretty sure they use the same lenses so the coverage is still the same.
I had them about 4" above the water when they were on the 90g because the gooseneck was a bit small. On the 120g I bought the 90degree adaptor for them and now they sit about 8" above the water and I've since reduced them from 100% down to 70% power. I use the kessil controller with them so it ramps up and ramps down. Biggest let down with these lights is they aren't dimmable between 0 and 10% or 20% so you can't do a true sunrise/sunset. They're off and then they're on
Even with them higher and lower power I still have a good carpet of dwarf hair grass growing, nothing else is really demanding high light so it's going fine. I'm really happy with the lights, I know I can grow anything and won't have a need to ever upgrade them for a freshwater set-up.
I debated back and fourth on getting the 160's as well but am really happy with the larger light. If you're already debating it then you might as well just bite the bullet and make the investment.
...if I take the dishwasher out and use paper plates I can put a tank in the kitchen without losing counter space