I still have to convince myself that espresso is worth the effort. Until I do, my next purchase will be an egg.
Results will come much easier, faster, and sharable with the BGE.
I've said before that really good coffee is a lonely thing. Some of the best coffee we will ever have is standing alone in a kitchen and even if you have 9 people there you can't really share the experience because it's really hard to find people that get it.
Espresso is so much worse in this respect.
But it's pretty easy to find people who like grilled chicken and I think the learning curve is quick on the Egg.
If you are not sure yet I'd go for the egg.