I, too, wondered which lounge to visit last week with our 3+ hours in HND. With OW Sapphire status we didn't qualify for the JAL First lounge, but we did manage to visit the JAL Sky View and Sakura Business lounges, after spending an hour at Cathay (until they closed at 17:00). BY FAR the better food/ambiance/etc was to be had at Cathay. We enjoyed several to-order dishes from the Noodle Bar. All were really fantastic and would challenge some of the better such food we had while travelling and eating out. There were hardly any folks in the lounge at Cathay.

At Sakura's Business lounge, as others have reported, it was quite busy. The food options there were far less appetizing (I scouted before we moved downstairs, and based on what I saw we ordered another round at Cathay's lounge). Drinks were pretty similar between the lounges. And Sakura vs. Sky View lounge on L5 (also a Sapphire-level lounge that opens at 18:00), Sky View was quite a bit less crowded, with the same drink/food offerings as Sakura's. The only difference was that showers were available in the Sakura lounge. I saw massage chairs on the lounge map but forgot to actually try them out.

Anyway, in my mind, with limited other options as far as how to spend our pre-flight hours with a couple heavy bags in tow, I'd vouch for showing up at HND early enough to peruse the offerings at the Cathay lounge. Hope this helps someone!

p.s. all 3 mentioned lounges have combo-code lockers where you can safely stow away carry-ons while perusing the truly crappy selection of goods at the Duty Free shops (we're not in the income bracket required to shop at some of the fancier designer shops, and the basic duty free shops were super disappointing after having shopped in real shops in Japan, and in European duty free shops.