- Visualize everything on a map. This is big for me just to help organize what days it makes the most sense to do things - Estimate travel costs (e.g. Ride sharing) based on distances between stops - Easily adjust number of attendees. Some costs are split regardless of how many people attend, like hotel rooms, while others are a fixed per person price, like event tickets - Ease of use for someone NOT familiar with spreadsheets. My wife couldn't replicate any of this in a spreadsheet, but she can use Itinee.
Some of the above may in fact, and probably is, possible with some fancy spreadsheet shenanigans, but the main point was to make the whole process more accessible.
I'd be really curious if the advantages I mentioned weren't apparent on the website or if they simply weren't, in your view, "enough" of an improvement over a spreadsheet to justify paying for it.