What Thief do you use?, among the existing NPC's, anyhow... Options

[geh4th]

When choosing among the available NPC's for party thief, who is the most viable and useful long term? I've often had trouble considering any of them very useful at all, aside from pre-IA Imoen.

For this discussion, I'm not considering situations where the protagonist is a thief, nor multiplayer (created) NPC thieves. I know that it's possible to make the 'perfect' thief this way. This is instead for players who want to use an existing NPC with scripts, banters and the like.

So among the original set of thieves, we have Yoshimo, Imoen, Nalia, and Jan.

Two of these can be written off right away:

1) Yoshimo - well, most of us know why we generally don't think of Yoshi as a "long term answer" to fill the role...(and if you don't, I'm not going to say anything more. Good luck.)
2) Imoen - no longer a thief with her change to Sorcerer in Improved Anvil.

This leaves us with Nalia and Jan...

Nalia is a Thief-4, with what I consider to be woefully inadequate ability in picking locks, even with the redistribution of her thieving skills. And you can just forget doing anything sneaky with her, she has no other skill at the "sneaksman trade" at all. I know that many people find her annoying, too, but she can rise to great heights as a mage later in the game.

Jan is a reasonably capable thief and an Illusionist, which makes him useful - if you can stand him. He's multiclassed, so progression in both classes is slow. He's a liability in combat for the most part, and I'd imagine he's not most people's idea of a good secondary mage-type to have around (but I might be surprised.)

It's my opinion that Nalia should at the LEAST be pumped up to be exactly what Imoen was before the IA change: Thief-7/Mage-8 (dualled). This would give Nalia 75 more points worth of thieving skills to apply to the big one - open locks - and to stalk/hide etc.

I'm sure players have other enterprising solutions among Mod-added NPC thieves and with multiplayer NPC-created thieves. I'd like to hear more on how you guys handle the situation.