"This is just like Brand X, but 5% cheaper, 10% faster, 20% easier to use and it comes in chocolate..."Certainly it is worthwhile to be clear about just what the competition brings to the table relative to you, but you will benefit more from highlighting what makes you different and unique, what separates you from the crowd, than by comparisons that serve to make you part of it.
In the end we want our audience to remember us. It is unlikely they will if we only highlight how we are like everyone else. Use your points of commonality to indicate how you have the fundamentals, use your areas of difference to highlight how you bring 'more' to the table than others. This is what will set you apart and get you remembered.