I use Candies pedals. The tension is not adjustable as it is on some other pedals, but they do sometimes have interference with the tread on the bottom of your shoes. I had one pair of shoes I had to cut a bunch of the tread off around the pedal or I had major problems clipping in, especially on the right. Very frustrating, I agree! The shoes I use now (Keen Commuter Sandals) I didn't have to cut at all; they work great with Candies.
Speedplay Frogs are very easy to get into and out of, but you shouldn't give up on Candies so soon; they are great pedals and will get easier and easier to use over time, assuming you aren't getting interference with the tread of your shoe.
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow