I've stayed only once at the old IC Bucharest (the large big tower) : i was fortunate to experience the same vibe when my grandparents toured behind the iron curtain, all though in a wonderful positive eye opening way of life changing experience,

Missing old IC DUS, now my DUS visits have moved to Hyatt's Wellem Wellem

Soft spot for IC FRA, after rediscovering my RadicalFaerie self at https://www.folleterre.org/en/home/ , (great supportive experience)
It came crystal clear to me that i am not some jungle person bathing in a lake and that i'm a slave to modernisms like plumbing : WC and hot water to shower. At IC FRA, i worshipped G-d for his wisdom of inventing the bathtub with adjustable water temperature and the sheer bliss of the Water Closet throne seat.

Unfortunately did not get to experience the older IC hotels as the budget back then was limited to HI & CP.
Of which HI/CP Singapore at Scotts Road was my first introduction to the concept of "hotel".
It turned my older sister into a Hilton devotée, it turned my older twinbrother in a Hyatt snob and fortunately myself firmly entrenched in the comfy arms of the IHG bubble.