I have been working on commercial products for a long time and repeatedly have seen companies compete with similar solutions. Often one is the technology leader and innovates while the other plays catch up and only survives by clever marketing. Sometimes the laggard can become the market leader, but typically only if the innovator makes a mistake (the classic example of a market leader losing ground due to a mistake is when New Coke came out).

When it comes to software products the rule is pretty simple, mistakes in usability are the ones that cost marketshare fastest. Customers are pretty tolerant of technical issues and bugs since all sofware has them, but if the user feels stupid when trying to use your product, they will switch very quickly to an alternative.

Bottom line is that mistakes of ususability are more costly in a competitive market than almost anything else, design wisely.