Hi Sarz,
Really hard question! I had always thought that 2 looked like the way to go. The chances of twins seemed so low and it increased the chances of getting pg sooner - and could an instant family be so bad?
BUT, my FS was dead against anything other than one at a time, and then when DH and i tried to bring it back up with the nurse she was dead against it too.
I am still in the down reg phase, but we have signed up for just one transfer whenever we get to that stage (hopefully before the end of the month). They have given us pages of info/stats, and it all points to having just one.
We aren't going to blasts - i think one is the rule with blasts.

I will be interested to see what the ladies who have been though it have to say.

Good luck with your decision.
Jo