I bought iCash some time ago and use it ever since for my private account. It´s easy to use - I didn´t even read the small manual, but was nonetheless able to set up my accounts needed and do transactions and analysis. This is mostly because the interface is clear and easy understandable.
You don´t need special accounting knowledge, because of the single-entry accounting, but a bit knowledge may be useful in some nitty gritty seldom used transactions. Changing and replacing transactions can be done easily, though, and allows you quick try-and-error in case you need it.
I especially like the statistic-feature to get informed about how much I really spend for special hobbies of mine (and where to cut expenses therefore...).
The possibility to group several transactions taking place in more than one account into one, or to split up one transaction taking place in one account into several goods also comes in handy, as it allows you a reflection of your everyday transactions, which may not always be so simple as one good - one account.
Support is excellent. When installing 10.4 Tiger the statistic-feature didn´t work, but an update with a fix was quickly available, and now it works smoothly again.
The only downer is that it´s a bit slow, and needs considerable processor power, but it did work stable so far (4 months) without crashes (working on a G4 iMac).
I´d recommend it for private users and small businesses.