Usually, they would wait as long as possible to convert - simple conservation of capital.
On a practical level, the 6 month SEC rule does not mean much, as anyone with sufficient capital and market savvy to have participated in the convertible offering(s) would also have the wherewithal and contacts to immediately short the stock against the shares they convert at any point in time, thereby effectively locking in that day's price for their shares.
If I could afford to buy all of them, I would not need to buy any of them and I sure wouldn't be spending time on the message boards!
