So how long does it take? That is what I wanted to find out. I conducted a little experiment with both my ING Direct account and my EmigrantDirect account. Last Tuesday at 9:30am CDT I logged into both accounts and put in a request for an immediate transfer of $10 to my linked checking account (both are linked to the same checking account). I then waited to see when the money would show up in the checking account.
The money from EmigrantDirect showed up first. My checking account registered the deposit on Wednesday, one day after I initiated the transfer. ING Direct took an extra day. It didn't show up in my checking account until today (Thursday). So if you're concerned about speed of transfers, EmigrantDirect seems to be faster.
Of course this is just one example. I'll continue with some more of these experiments in the future.
BTW, if you're interested to see how ING and ED rates have compared this year, check out this chart that I generated.