I think I echo the sentiment of others by saying that I prefer to work with almost any other cleat and pedal when it comes to bike fit. But I think when it comes to really trying to improve what we do - we must learn to embrace our weakness or area we like the least.
I personally took this challenge and one of the results was the new V V 1 cleat, perhaps the most advance cycling cleat in the world. Here are some of the considerations for taking this challenge.
Market size and share - The SPD market is the largest market of pedals in the world. I will restate that as there are more people (A LOT MORE) riding some sort of SPD or SPD knock off than any other cleat and pedal. This is a huge and relatively untapped market. It really is ours for the taking.
Mtn bike fits and control - When it comes to so called mtn bike fits I often hear people say bike fit is not as important as a road bike. This could not be further from the truth. What controls a mtn bike more, than lets say seat height or position, is the foot/pedal interface. Your feet control the bike and are far more important for control of the bike than they are on a road bike.
The kicker – in spite of the fact that the connection is more important the platform size is small and not as stable. – The relative contact surface of an SPD cleat to the bottom of the shoe is so minimal. Often efforts we put into working with this cleat have been tough. Even when we get a desired adjustment it can be difficult to make sure everything maintains its setting. One less variable (incorporating a wedge into the cleat) eliminates one of the adjustments we need to control when working with SPD cleats. In other words it should be easier to address by eliminating one of the reasons we may tend to shy away from SPD type fits.
Here is a link to some early success with the V V 1 cleats. I hope you too will enjoy this type of success soon. http://hypercatcycling.wordpress.com/