I had a requirement to create a web-based application that would create two pivot tables. The data source was SQL Server and the user had to be able to filter the data before populating the workbook. The XlsIO solution was both elegant and simple. I used XlsIO to open my existing workbook (which contained the pivot tables), populated a sheet with the desired data, reset the data source range of the pivot tables to use the new data and saved the new workbook for the user to download. I had never used XlsIO before, yet by looking at a couple samples, their online documentation and some posts in their support website I was able to complete the project in a few hours instead of the couple weeks that I had thought it would take. I did run into one problem - one of the argument types to a function didn't match the documentation - it wanted an int[] instead of an int. The routine still worked by setting x[0] to the value I needed - I figured that it must have been an oversight so I submitted a bug report. The support experience was really top quality. Syncfusion communicated at every step of the process. A support tech told me that he had received the report and was looking at it and gave me a date by which he would tell me if he could reproduce it. That date was met and he then told me that the bug had been forwarded to the devs and gave a date that it would be fixed. That date was also met and I was given a link so I could download the fix. The great thing was that the fix wasn't just a dll - it was wrapped in an installer that updated the proper files and also put them in the GAC. After a few days, the support tech emailed me to verify that the fix had actually solved my problem. The communication and attention I received made me feel like Syncfusion cared about me as a customer and that they take great pride in their products.