My two cents is that if the only reason you're doing it is to get the lumberjack outfit, temple trekking is not worth it. I did the math, and for me, to get to 99 wc from 73 would take about 66,000 yews. With full lumberjack, it would take about 64,000 yews. In theory, since I will level faster, if my goal was to cut 66k yews, I would be able to do that faster as well with full lumberjack. However, there are lots of other rewards in Temple Trekking too. Watermelon seeds for farming, silver bars for carfting, iron and coal. The events can give you snakehides for crafting, nail beast nails for herblore, etc. If you're well rounded in the game, I think the temple trekking is a fun minigame with lots of useful rewards. Mostly, I'm going for the full lumberjack outfit because I see so few of them.