AR-2 EZY
First tried them without the clips and the right pedal came loose
Came loose however is not the same as coming right off and it did not cause a big problem, I just stopped, snapped it in put the clips on and carried on.
Used clips for about a month then eventually lost one
Have run without clips since then (couple of months) with zero problems
The retention collar was initially a bit stiff and I suspect that my initial problem may have been that either I didn't get it locked in properly or I bumped it and it was too stiff to snap back into place.
Bottom line: They seem OK without the clips provide you make sure that they are properly snapped in but you may need to take a bit of care initially.
David