Memorize this: “I have some concerns, but I need a little time before I can really articulate them.”
If you're a manager, or anyone who leads meetings and discussions, please PLEASE have respect for that phrase. It's unlikely (but possible, sure) that someone will abuse this, since “buying time” in the context of a work decision doesn't usually buy us anything other than the chance to think more deeply.
Are you stuck with a legacy PHP application? You should buy my book because it gives you a step-by-step guide to improving your codebase, all while keeping it running the whole time.