It has worked extremely well. I haven't had one fail yet. I've done it about a half-dozen times, now. It's amazing how fast the Top Bar hives becomes fully established using this technique. If the flow is weak or non-existent, it may be necessary to feed generously. Sometimes, to get more of the Top Bars started with comb, I put a few of them in various hives, then round them up when I'm ready to do the transfer. During our mesquite flow, some hives build nearly complete combs on the Top Bars, overnight and filled with eggs.
If the Top Bars are shorter than Langstroth Top Bars, I fasten them beneath a strip of wood that is the length of Langstroth Top Bars, and if the Top Bars are longer than Langstroth Top Bars, I just let them stick out on one end.