I absolutely hate those prefabricated concrete borders. My street is one of the only ones in my city that has them and there's a good reason for that (QC, CA). Theses things just don't stay in place unless you place at least as much concrete behind them as you would have for a poured in place concrete border. They move around, end up in snow piles during winter. My city promptly discontinued use of those and went right back to poured in place borders.
