Liquid force have some good lace up pads, that haven't suffered from the same issues as last years syncs so would be worth checking out.
I havent seen the Flexi pads, but it doesn't hurt to try a few different types what some people like others hate, personally i don't like supper tight foot pads, i just like them to be firm and have a fairly even pressure across the foot, with the toe grip in the right spot.
Are you having problems keeping your board on while jumping/landing or popping?
If so it could actually be caused from a problem with technique.
Which foot pads are you using at the moment?