I have one, and I get 5.4% interest per year. On June 1st, they're increasing it to 5.6% per annum.
No annual fee, and no fees for anything else for that matter.
My funds are transferred from my ING account to my "regular bank acount" by the next business day if I transfer before 4pm the day before. I've never had a problem with running out of funds in my "regular" bank account because I always leave $100 in that account. This gives me around 1 day where I only have access to $100 in my bank and the money currently in my wallet (usually $200). I can live with only $300 for 24 hours, along with my credit card (nothing owing on it), and an account I have in Canada.
In Canada, I use PC Financial because I have a high interest savings account (of only 3.05%), chequing account (free cheques!!), and credit card is also with them (easy to pay the cc bill), and it seems easier than ING.