Using this application in my office for over a year now, I am can safely say this application is unequaled on the Macintosh. I have since put away my financial calculator.
While this is not the reason why I bought this application, I later found some other applications to be seriously flawed in their calculations. I base my test upon both the Loan template in Microsoft Excel and my loan calculator. I found iuLoan to be accurate to within a cent in almost every situation I have tried. Importantly, it is consistent with Excel. For example I put into the excel loan template: $250,000 loan at 8.25% over 30 years and 12 payments per year and iuLoan and excel agreed upon the total interest, total payments, and the principal and interest of every period in the amortization schedule.
2. User Interface
Not only is this application easy to use it also looks good when showing my clients. I found the brushed metal a disappointment at first, but since Apple seems to be bringing more metal out all the time, I am getting used to it. The graphs are great and the way information is divided across the tabs is also a plus. I am glad the developer elected to keep a calculate button. This gives me the same feel as using my financial calculator... some on-line apps have tried to remove this. The icons are good and in keeping with the quality one expects from an OS X application.
I have owned several versions, and it just keeps getting better. I have made some suggestions to the developer over the last year, and most of these have been implemented. In fact the only major suggestion I have not seen so far, is a French version. iuLoan lets me print or save any of the loan information it generates. It also lets me work on multiple loans at the same time: I use one for figuring while editing a working loan (side-by-side). It has a loan comparison tool, but I prefer to do it this way. One of the biggest pluses I have found is the ability to export the schedule to a comma file. I often use this for import to Excel. iuLoan comes with a bunch of tools as well, which I don't personally use much, but its a nice addition. The built in mini calculator is nothing but handy.
A good financial calculator might cost more. This software in my opinion is priced correctly. I would have paid more (say $45) if it came in more languages.
I have had a prompt reply to every question I have had so far. They even have a small support forum with some information. The has various help links built in, including a link to a bug report form. Support for this product is excellent in my opinion.