I approached eating it as I would a grapefruit: I sliced it through the equator. The rind was between 3/4" and 1" thick, the 'meat' was irregularly organized, making the cut-around-the-outside-and-dig-it-out-with-a-spoon technique worthless. The 'meat' was fairly dry and the cells fairly tough though so it turned out that just picking it apart with my fingers was not too messy. It had about 1 1/2 regular grapefruits-worth of 'meat'.
At first I thought it was a mutant grapefruit (the flavor is nearly identical) but the growth pattern is very differnt in this way: the cells go sideways or circumfrencially instead of radially. The seeds are really tiny (.5mm) and I have no idea whether they are viable... yet. (well they didn't sprout for me. :-\ Any tips for sprouting a mango pit?)
On the whole, especially given the price, I'd rather have a grapefruit. If your experience with these things differs from mine in a way that suggests that I got a bad one, please tell me about it.