Okay, so I have been to both lounges and it is literally night and day. The G/H lounge is small and dark (to me), while the K/L lounge is large and airy. I am glad that I tried both, as the Champagne offerings are different. G/H had Cuvée Louise 2005 and advertised an oyster trio (along with a veal menu that I did not try):

I didn't ask what had been renovated, but other than the nice-looking bar, the lounge did not look particularly modern to me.

K/L had the PN (and some others) and advertised the asparagus, which I had with schnitzel, followed by an espresso on the terrace:

Ultimately the service at both lounges is quite good, but I wouldn't want to spend all day at G/H, whereas I would happily spend 3+ hours at K/L, as I'm now doing.