One of the first differences between the two is that TripCase does not offer an iPad version, which is a bit disappointing. Perhaps this will come in the future? Both offer two methods of entering trip data - manually, or importing (via email confirmations). In this respect, both operated smoothly. Currently, even though I have two additional trips planned, I only have the data available for my next trip, a cruise. Once I finalize the bookings for another trip, I will be able to compare the two apps as far as multiple trip list views.
TripIt also allows me to connect with others who have TripIt accounts - a nice feature for business travelers and families. I use this feature often. TripCase looks to have this same functionality, although I have not set it up, as none of my existing contacts have TripCase accounts.
Both apps also have the ability to publish information to your social networks (Facebook, Twitter, LinkedIn), although I'm not sure I'd want to share that much.
Both apps also have the ability to share your trips to your online calendars, via subscription, something I use all the time.
Both apps have associated web sites which also allow for manual entry of your trip info, although I personally prefer the layout of the TripIt site. Both apps have free and paid versions, but I do not yet know what the cost of the Pro TripCase account is; I've been unable to find it on their site. TripIt offers their Pro version for $49 a year, not really a bargain unless you're a road warrior.
One of the features which caught my eye with TripCase is its notifications - when I land, TripCase will let me know if a connecting flight has changed, or remind me to check my hotel to see if I can check in early. It will also provide traffic updates if I'll be driving to my next destination. TripIt also shares some of this functionality, but at a $49 per year cost. right now, while TripCase Pro is free, that will be my preference.
Overall, both apps offer nice visuals and comprehensive features, and I'm looking forward to exploring their differences on my next trip.
Ok, the verdict is in - it's a tie. No, seriously. I have two more trips scheduled this year, and will continue to use both apps. I really can't decide which I like better. At least not yet.