I stayed here two weeks ago, and this was a really good perk for me, and anyone else travelling with kids, as a lot of Japanese lounges ban children during happy hour (i.e. 5pm onwards) - so nice to confirm that it has been maintained. The full breakfast offered by default for elites was tasty and included an omlette chef offering a local oyster omlette amongst others.

Otherwise my reason for returning (as a tourist) is due to location - being right next to the train station/Shinkansen (and connected via a covered walkway) makes it really easy to get into/out of Hiroshima, and for doing day trips. We did a day trip to Tsukushima-jinja on Miyajima Island easily with a direct train to the ferry terminal. And getting around the city is very easy with most tram lines terminating at the station, and the sightseeing bus loop lines starting at the bus station too.

Whether it is worth double the Hilton is however subjective - it isn't walking distance to the sights so you will need to take public transport. The Hilton doesn't look to be that close either though so you'd be taking a taxi from the station to get there I guess.