Power Training is the way to go - no question at all about that. As a coach I want power files for all the rides my athletes do so I can plan and track their wattage progression and accumulation of training load overtime with the
Power meter choices for the mountain bike are tough. On the road I've been running Power-Taps without a hitch for a few years now. Thumbs up for Power-Taps. The PT measures power at the hub and they don't have a disc compatible hub. Thumbs down for PT. That is a deal breaker for me off-road so PT is out for mtbing.
As a coach I am desperate for a power meter that works well off road. That is an expensive wish as it means I have to try them all out. I've been riding an SRM on my mtb for over a year now. It has so many limitations I cannot recommend my athletes sink their $$$ into a product that is less than ideal.
Next up on my list for testing is the Ergomo and possibly early next year I'll get my hands on an I-Bike (working on that deal at the moment :-). On paper The Ergomo looks like da bomb. It has everything I want. Now I have one sitting here in my office all I have to do is install it.
First off Ergomo wins the presentation award hands down. My PT came taped up in bubble wrap, the SRM came in a nice white cardboard box but the Ergomo comes in this little metal 007-like attache case. How cool!
Here are the three CPU's side by side. The SRM is the monster - heaviest too. Finding room on my bars for a hulking CPU is always an issue - especially in 24's when I have to put lights on there too. Ergomo lurks in the middle of the field here and at first glance looks like I'll be able to set it up on my stem. The SRM is a bar mount only. The PT can go both ways. The PT mount is zip-tied on so will go anywhere I can get zip-ties.
Now I'm off to the Desert Cylery to have the talented and patient wrench Andy watch over me installing these beasts by myself. Currently I have Andy busy fixing one blown brake line and three blown forks. I love Andy :-)