Blue Lagoon has the better resort grounds & ambiance; Truk Odyssey is the best of the recreational itinerary liveaboards (now finally providing banked 21/40 Trimix as needed for the deep San Francisco Maru) ; but the Truk Stop Hotel/Truk Lagoon Dive Center has the better tech diving support --the only dive operation in all of Micronesia with Helium readily available for mixing any desired blend of trimix and Oxygen for Eanx30, and deco mixes of 50% and 100% always available as well. Blue Lagoon Dive Shop will only guarantee He & O2 supplies if you pre-order months in advance (they now have an Oxygen generation system finally installed, but only at FO2 90% at best), while Truk Stop always has the gases for the ad-lib/drop-in traveling tech diver (larger groups though should probably call ahead).
Also, for the deeper wrecks of the Fourth Fleet Anchorage (San Francisco Maru; Aikoku Maru; Nagano Maru etc), or the Oite Destroyer at 60m and the deepest lagoon ship Katsuragisan Maru Wreck at 67m plus, the Blue Lagoon Guides on single tank will only escort you down to the wreck and rarely guide you through, while Truk Lagoon Dive Center Manager Rob McGann or Dive Guides Nuwa & Jerson on double AL80's will personally lead you on penetrations of the hull, cargo holds, superstructure & engine rooms and do the decompression profile along with you (if you're Technical Wreck/Trimix qualified). . .
Just returned to LA after three weeks at Truk Stop Hotel and a week in Palau to vote in Calif Midterm/Gubernatorial Elections today, and will be returning to Truk this Sat for another two weeks of diving the deeper rarely explored wrecks. . .