The rib bender is a piece of kit I "inherited" when I started running the workshop. It was bought back in the 70s when the department was making a lot of wacky woodwork.
To explain that, I run a workshop at a university design school. The main focus of the department in the 70s was furniture and ceramics, now it's industrial design but we kept a lot of the old kit because it comes in handy every now and again.
The rib bender is basically a big lump of aluminium about 3 inches tall with a heating element which you can pull wood around to heat form it. (see pic).
There are no real pitfalls as I can see provided you work methodically and watch out for the symmetry. I test fitted the ply skins repeatedly until I was happy that they touched in all the right places then maked a couple of reference points on them so I wouldn't have to check the position after the glue was applied. Basically glue it up, lightly clamp it and then line it up with the marks and get the rest of the clamps and pins in place all, hopefully, before the glue sets.