One of the golden rules I have always applied to anything I do is to never criticize my competitors, here is why.
You never know what they or you will do next, they could be partners soon. I have many ex-competitors who became very close friends helping me all the time.
It is bad publicity for you, focus on the positives and improve your own product than try to criticize others. You build a bad image for yourself if you keep criticizing others.
They could buy your company. France Telecom launched in 98 a product directly competing with mine with an ad that looked like ours. Instead of criticizing I took them to lunch and a few weeks later they acquired my company.
Competition is good. Celebrate competition, it kicks your butt to deliver a better product faster. Celebrate it and just be better.
Competition grows your entire space. The more players on the market, generally the bigger the market.
Meet them. Have lunch. Exchange information. Both of you will learn. Don't reveal all your plans, but some sharing is really good.
You could work with them to grow the space. I had launched with competitors in 96 the French Chapter of the Internet Advertising Bureau. We defined format standards for banner ads, put together a book and we all got more business from sharing and working together.
Say your competitors have great products and recommend them, you will build trust.
Even if the temptation is very high when you think what you do is better, never criticize them. If you want to be extreme, you could do what Robert Scoble does, instead of pitching his product, Robert pimps his good competitors and explain what are the important criteria to make a choice. A conversation starts and his image gets reinforced by the community reactions.
That is also what Tony Hsieh the CEO of Zappos does. If you call customer service and they do not have a product in stock, they recommend you to a competing site. The result is they are happy about their experience and likely to come back to you first next time they have something to buy.