Honestly I don’t like to hear the following opinions: “I know those guys and they are really awful”, or “I could tell you some terrible stories about that firm…” It’s because every coin has 2 sides, right? And the other party is not there, to protect his product/service, or company.
I have my own strategy and I never judge the competitors during a client interview, just to be the choosen one. I only say a few words about the known strength of the software, so the client can make his/her own conclusion, if it’s fit, or not for the requirements.
What I usually say, like “that’s a quite good software, neverthless, you grew over it” And it gets us on the same page immediately, without creating dislike.
What’s more, I also feel better 🙂