Its easier to look like a rockstar by getting a 30 day estimate done in 10 days than a 10 day estimate in 10 days when it took 30 days of work. You'll rarely get extra credit for meeting expectations.

The bit that stuck in my head (from Code Complete or something like it) was the phrase, "Watch out for people who look more productive than they actually are." As in, not writing tests, or making bad decisions that take 10X the original effort to fix, or that write systems that fall apart in corner conditions, or . . . (the list of problems is large).

I like to think that most big-ish products can be divided into three equal parts, each consisting of 90% of the work. It's that third 90% that separates the decent products from the great ones.

[Yes, I can do math. I mean that you get to your original 90% goal and realize you've still got a LONG way to go.

"Problems worthy of attack / Prove their worth by hitting back" -- Piet Hein]