This is really a great concept, and I'm a little bummed that this new offer excludes those of us that accepted their last offer. I'm going to horde hotel points for a little while now to see if they offer it again without the restriction. Based on the wording, perhaps they'll allow you to do it once per year.
I did this when they offered it last year. Only had one minor hiccup. On one day I transferred 300K miles, which should have translated into 60K Asia Miles, and subsequently a 30K bonus. When they released the bonus, I only received 18K miles. It took some digging but I finally figured out what happened. IHG will only allow you to transfer a maximum of 120,000 points per transaction (which translates into 24,000 Asia Miles). So I had to do two 120K transfers, and one 60K transfer. It translated into two 24K Asia Mile deposits, and one 12K AM deposit. I think someone (or some program subroutine) thought the two 24K transfers on the same day was some error, and so they only awarded for one of them. It took a few emails to MPC and maybe 4-6 weeks to get it cleared-up.
Anyway, the 90K Asia Miles are much more valuable to me than the 300K IHG points, so I hope they do this again! :-)