Not to add to the flames Eaglestrike, but Nebo1 also specifically said that he is using RR/GH/SS for atmas, which means that he doesn't have 35% TA rate. At most he has probably 16%, since with a Twash/Daka he probably isn't offhanding a Triplus dagger. On WS he is probably still at 10% due to equipment swapping.
For my merits, I have 5/5 Feint, 4/5 AC, 1/5 AS. Personally I don't use either AC or AS very often. The best utility I have found for AS was recently when I was low manning Blanga, I would occasionally get his attack buff from him. Quite often his very next TP move would be Triumphant Roar again. Don't get me wrong, I much preferred that to Terror Eye/claw attack of drainage. There are arguments for both, I am seriously considering dropping my AS merit myself. The only reason I haven't is I don't really ride my AC timer either. Ambush is totally useless to me as I am quite often the first one to the hate cap on whatever we are fighting.