The functionality is pretty buried.  If you're accepting a walk-up event attendee at a paid event, it takes quite a bit of time to add their record to the event, and then tap into their record, add event fees, and pay those event fees.

Additionally, it's nice that you can charge the attendee for multiple fees at once, but it would be fantastic to be able to soft credit/add payment those additional fees to the other attendee they're paying for.  For instance, if I'm paying for me and my spouse, have one payment apply to my record and the other apply to my spouse's (or soft credit) so that the database admin doesn't have to go through the event after-the-fact and move payments around to cover fees.

It would also be great to be able to use the BBMS card swipe instead of having to manually enter that credit card information when charging event fees.