I don't mind system when used to define a character's capabilities, but in actual forum RP I prefer consent and negotiation to die rolls.
For example, if Greenthorn's character has better combat stats than mine and we come into physical conflict, I've no problem at all losing without ever rolling a die, and yet, if I come up with a clever RP way to 'cheat' or negate some of her advantages, I'm sure I could discuss it with her via PMs and work out a resolution we both like.
And I feel the same way about PC versus NPC challenges.
Why yes, I am a fan of Amber Diceless. Why do you ask?