I used 625's all the way round and they were plenty of power.

I also know some people are having good results with the Savox servos but I am not familiar with their model numbers etc.

Another thing I did with mine was to use 4/40 pushrods (made from 4-40 threaded rod with some carbon tube glued over them) as the ones supplied (I guess they were 2-56) were a little flimsy for high throws for 3d'ing.

I will take mine down from the shelf tonight if I get home in time and see if there are any other mods I remember doing to it.