The idea is good. Straightforward and reasonably versatile. However it needs work. After ten minutes of playing with an account, I encountered enough to make me want to hold on to my money for a later version. A few examples:
When you select a New Group or Item in the Categories window ... The name field should come up ready for typing. You should not have to double click to make it receptive.
Command N should automatically produce a new group or item depending on what is selected. If the transaction pane is active, it should automatically enter today's date in editable format.
The drop menu for selecting a category does not work if you use the cursor to select the category. However it does work if you use the down arrow and then press enter.
Not a good begining.
I am running OS 10.4.2 on a 14" G4 iBook 768 Meg RAM.