Just left Singapore out of T3 and I can comment on both......
The Silver Kris F/C lounge is great in T3!!! Real spacious, great food, and of course they serve Champagne throughout the day!!!
Much better than any of the T1 and T2 lounges in Changi airport!!!
I spent time in both the Biz and F/C lounges and I will have to say...the experience from ambience, food and drink is identical.....The Biz class lounge is actually bigger than the F/C lounge.....^^
Also, in the new HKG F/C lounge and it is much better than before....more spacious....better location of the TV.....new furniture....thumbs up to Armando V and his crew in HKG!!! ^^^