I can't see the bottom one clearly, but I don't trust the aluminium lip that they put around the edge. It distorts fairly easily and when it does the case becomes difficult to close. If the bottom type has the same lip I wouldn't trust it either. I think it is the same type as this one though, which doesn't have a lip like that in these photos and seems sturdy:
http://www.everythingsg.com/threads/new-gator-case-day.27568/
Thanks for the info. It's not something I've ever really thought about tbh as I've usually just used whatever came with the guitar
