Be careful what you say about your competition
People don’t like it when someone is attacked, especially when the attack seems unjustified or there’s an underdog being attacked. This is a reasonably common human trait that still operates in the world of business.
So, if you are up against a competitor with a prospective customer you should tread carefully. I’d recommend that your proposal talks about only about the way you’ll solve their problem. Remember that part of the problem they have is in choosing a solution amongst different vendors. Build trust in your brand and solution.
Don’t go cross the line into slamming the competition. This erodes trust very quickly. You don’t know the relationships the prospect has or where that information will end up. You had better hope all the facts you used about the competition are totally squared away.
Be a company others want to do business with. And stop helping the competition.