Xcellery handles real world spreadsheets.

A friends company is interested in using Xcellery for their sales team. For test purposes we got one of their workbook's which contains several worksheets and makes strong use of cell merges. Out of curiosity I imported the workbook into all the well known online spreadsheets. None of them was able to handle it. Many already failed during import or became very slow while editing.
Using Xcellery we created a new workbook and opened it using "Edit in Excel". Then we simply copy/pasted sheet by sheet from one Excel file to the other. Everything worked smooth. This test showed that browser-based-only spreadsheets aren't ready for the real world yet. Xcellery using Excel on the other hand is.

Stay tuned, Xcellery import is coming soon.