Describing your product as “the only choice” when there are actually other choices is a fine display of cockiness (or a display of market ignorance, but most likely it’s cockiness). This suggests an honest belief in the superiority of the product. But describing your product as “the only choice” when it really is the only choice suggests something entirely different – it says, “We know this product is crappy, but it looks like you can’t complain.”
MLB 2K6 preferred the latter, and I can see why. “The only next-gen MLB game,” it said. The game has the most horrible interface I’ve ever seen. Options are buried deep within sub-menus and the game must be saved in at least two or three places every time (if you want to keep your stuff). But it freezes, and that’s the biggest problem. You can’t make it through nine innings without having to reset your Xbox and try again. But you don’t want to try again anyway – fielders move like they’re crawling through molasses. Simple ground balls shoot through the infield if you make the slightest mis-touch on the joystick.
So, to summarize – avoid products which hype themselves as “the only choice” when that is, in fact, true. If they have nothing better to say about their product, it’s not worth a second glance.