I used the AI lounge on my recent trip on ANA from DEL to SFO through HND, and had a chance to compare and contrast both the AI lounge and ANA lounge in Tokyo.

Food wise perhaps ANA lounge is slightly better simply because they had more options.

The seating was pretty much comparable between the two. ANA lounge had no sleeping rooms, and not even enough chairs that could recline, but AI lounge had sleeping rooms available.

ANA lounge had slightly better showers (better toiletries) but also a wait time of almost 2 hours while AI lounge had zero wait time to use the showers.

So there you go, a review of AI lounge as well as a high level comparison with ANA lounge in Tokyo.

Mandatory caveat: sample size of one, and YMMV.