Anakin - quite expensive and I'm not that much sold on his ability.
Obi - great for... reasons
Plo - can do some crazy things or not... depending on your list and your opponent
Ahsoka -useful, even at I3
Mace - I just find great, slap hightened perception, 7B and R4-P17 on him and he is just beast. Probably my favourite pilot of all, good ability, 3 force and solid price.
Saesee - maybe useful, playing him, Mace and Lumi with hightened perc each against 4xI5 squadron was really strong but moving first didn't net me use his ability once, still I didn't need it.
Luminara - I found her to be quite good. The turns I didn't use HP and shot second made my opponent use his focus/force to push more damage trough or just settle with one hit which I evaded. Less useful when I engaged at I7.
Barriss - That one force is just bad and too expensive to even consider her in a list for me as I see Luminara just better.
Jedi Knight - 3x with Battle meditation, R3 and 7B were quite solid but not that great I won against high ini rebel list but my opponent just rolled bad. And as a support ship with cheap battle meditation pretty solid. But I agree, better to find points for named pilots with atleast 2 force.
I tried Gideon and Del with Kestal, Rhymmer and Vynder. They are still tie fighters and die too easily. Even if you have Iden, I don't think it's worth it, you pay 40 to survive one more shot and your 2 dice attack does not do that much. I would just sink points into other ships.