I have had good results using Salomon Speedcross trail runners and BD Contact crampons with the regular bars swapped out for flexible bars. The Contacts are easy to put on, take off, and adjust.
Note, however, that the heels are relatively narrow. The two metal tabs where the rear plastic binding attaches at the heel are set fairly close together, targeted towards most mountaineering boots, which seem to have narrow soles at the heel. They work fine with the relatively narrow heel on the Speedcross, but they do not fit my Salomon XA Pros, which have quite a wide flare in the sole at the heel. I had the same issue trying to use the Contacts with my old, now infrequently used hiking boots, which have a relatively wide sole at the heel. You can get the heel of the wider shoe/boot to rest *on top of* the metal tabs instead of between them, but I found with the boots that this results in a much less secure binding. I accidentally kicked one of the crampons part way off the first time using them, when using those boots. Fortunately, it was not in a safety critical spot. With the narrower heels on the Speedcross, they fit fine, and the binding has been very secure, not loosening noticeably over the course of the day.
Edit: Maybe obvious, but I should note these were BD Contact Strap, not the clip variety.