One, Three, Five levels in Master Thrower?

[Newbieshoes]

I'm currently playing in a game making a Human Rogue eventually going into master thrower around level 11. The question I'm wondering if do I want to go with one, three, or five levels in the class?

Small breakdown of what I can see so far. Assuming a 20 level game

One level:
Gains: point of reflex, better HD for 1 level, quick draw for free and my first throwing trick (sneaky shot). Level 20 rogue is a dead level
Cons: Weapon focus is a feat that is, well, lacking. A few less Skill points.

Three levels:
Gains: 2 tricks (second trick, palm throw only have a +1 str so trading 1 damage for 1d4 isn't bad). Slightly better HD
Cons: Lose a die of sneak attack (lost special ability is made up for with evasion again for improved evasion) Less skills

Five levels:
Gains Weak spot (touch attacks), improved crit with any weapons I can use tricks with, snatch arrows, 16 BAB at 20) 1 better reflex save. Slightly better HD.
Cons: Lose 2 die of sneak attack 2 special abilities (technically 1 due to evasion again from MT). Skills again.

[Saint GoH]

Touch attacks are pretty ballin, as is the ability to throw 2 daggers with one attack.

You can make up for that missing 2 sneak attack dice by taking Assassin's Stance from ToB. Id say 5 lvls for sure.

[Rasman]

for a straight rogue I'd either take the 1 or 5 level dip, the 3 seems to be lacking, but the one is very nice for anyone who wants to throw and such

[gorfnab]

5 all the way. Touch Attacks are just awesome and Improved Critical for free is very nice too.