Even slighly curled film will pop the film tray open. It's pretty frustrating when you have a couple of rolls and you spend more time adjusting the fim tray than scanning...or having to rescan images because they don't sit correctly in the tray. If you do a search on the web, the reviews of the flimsy tray are out there. I'm not making it up.
True, I could buy the insert from betterscanning, but at $30 that's more than 30% the initial cost of the scanner (bought mine for less than $100). If I also wanted the medium format insert, that's an additional $30. The principle of it just doesn't make sense.
The Epson is a decent scanner, especially for the value. I just have gripes with the film tray.