that they put back 2 screened embryos but did not automatically go for the two best ones. That makes me suspect (my opinion only!) that they did that to put in one of each gender. Either that or they didn't want to "waste" the best two embryos on one transfer, just in case there was an unresolved recipient issue, they would still have a "best" reserved for next try.
Reason for the CGH testing and freeze-all is I've already had a child via DE but it was a long hard road, I don't want to go through that again while I'm enjoying just being a mom. Plus (no offense) I do not really want twins, only interested in SET with screened embryos.