Having only used Oracle, MSSQL, and MySQL, I can't imagine a small 500-user app would be that hard to implement in in Postgre even if I'd never touched the platform before - does Postgre have some terrifying gotchas, or does it work as a reasonably well-behaved SQL server? That is, if I naively installed a PostgreSQL server on my box and started creating tables and indexes and users, would I be destroyed by some horrible gotcha as I failed to account for some critical config (like selecting the right storage engine in MySQL)?