ronald on "Endometrin vs. Progesterone"

I'm about to start a FET from a donor egg IVF Cycle (first one BFN). They are doing it immediately following the failed cycle, using my natural cycle. Instead of the Progesterone Injections though, this time they are having me use the Endometrin Vaginal Tablets. Has anyone used these in the past, rather than the Progesterone injections? I'm from Europe and we only have the vaginal tablets, no injections, but I've always heard the injections are more effective.
Thanks.