I've been tinkering around the edges for a while now, but think it might be worthwhile to lay out where I'm coming from. In game system rule sets, I look for three things:
1) Consistency
2) Compatibility (generally backward, with previous editions of the same game, but also with other systems by the same company)
3) Playability
It seems to me 2 and 3 were the priorities for the current set of core rule books, and 1 suffered as a result. I think it would be useful to raise the priority of 1 if and when TPTB decide to embark on the next iteration of the rules.
That said, I'm going to try to stick to those priorities with the various house rules I post here. It's one of the reasons I started with
Power Packs and
Machine Guns. I would like the rules to be consistent from top to bottom, and it seems to me the easiest way to accomplish that is to start from the bottom and work up. If done correctly (or at least as correctly as possible), the abstractions made along the way will yield the table top game we're all familiar with, but with a firmer foundation. Some tweaks will inevitably be necessary (see my discussion on Power Packs), but I think the game will be better for the effort.