There are other lounges and better ones than Hilton T4 (and as Gold it's not guaranteed?). The HGI is vastly easier to get to, even for T4 users! But the right rooms from the HGI do give excellent views of landing aircraft. You want the rooms overlooking but to the left of the oval-ish conference centre on the Hilton OLCI map for arriving aircraft. You want the overside, top side of the S, for apron (ramp) watching.