When you are dealing with clients however, never draw attention to downsides.

If your goal is to be a bullshit artist, worth little more than whatever crap you’re peddling at the moment, absolutely - otherwise this is not good advice. And all you have to do is take thirty seconds to reflect on the last time you humoured someone who was being disingenuous about their value to you.

Done tactfully, being up-front about deficiencies can make the difference between being seen as a trusted advisor or another self-interested parasite.