I couldn't make the Lantau 50 this year coz it was on my Mrs' bday. How was it? I did the AA Sai Kung 50 instead. It wasn't as constantly technical - but the heat on the day and Sharp Peak made it tough. Where r you training? I guess Lantau / Tai Lam are best trail access for you?
Dan, I would suggest you hop on the West Rail to Tsuen Wan West, or Tung Chung line to any TC-bound stop basically. Tsing Yi has a great seaside running Track. Tsuen Wan too - and just outside the Tsuen Wan West Station