I've been using iBank for a year and a half. Despite all the promises, it is unfortunately very frustrating. The basic problem is that the features are nowhere near Quicken (2010 for Windows, what I used before). The other issue are the bugs - with each new release, I hope that the various crashes and weirdnesses are fixed, and sometimes they are, but then so many new issues arise. One caveat, the bulk of my use and frustration with iBank is with investments, if you are more interested in cashflow type of transactions, it might be better.
I feel that I send more time working round the issues with iBank, than actually being productive with it. Because of this, I've been seriously considering going back to Quicken, in a VM on Fusion. Obviously I would hate to have to do that though! I keep holding off, in case Intuit actually come out with a proper version of Quicken for the Mac, but I can't say I have much confidence in this ever happening.
So, all in all, I wouldn't recommend iBank...