More than 500 BTC net have been divested since the change came into effect, though admittedly that's less than I had expected. Whether that's because investors are "playing chicken" with each other or their demanded rate of return is lower than I assumed is hard to say. In any case, I have no doubt that the bankroll will eventually reach a saner size as commission rate continues to increase to match Bitcoin's price.

Regarding alternatives: I've seen some interest-bearing accounts for Bitcoin, but none that offer more than 3% per year. IMO that's way too low to justify the risks, though, especially the significant counterparty risk.