Thanks for the recommendations. My trainer recommended the pd-520 or 540. I noticed the 540 is a little lighter. He also mentioned the pd-324 which has a platform on one side - and is much heavier than the other two.

The idea of going clipless does make me a little nervous, but I am accustomed to it from spinning class, and the issues that are developing from NOT being attached to the pedal need addressing.

Performance Bike seems to have a good price on all three of this - and it is good to know that the 540 is considered a step-up over the 520, so will likely go with the 540 but I don't want to make a snap decision on this