I could never make progress. As much as I like these sort of things, the inability to repair items means that the best laid plans WILL fail and it becomes entirely to the luck of what you pick up in the next few minutes. So as much as I wanted to get into some good gear and spec out a decent build, I quickly realized that making a build was impossible and the only way to do anything was to make a mad dash to the exit.
For sure in the early/middle levels, IF you can stand the time it takes, it's pretty viable to play very conservatively and completely/near-completely clear levels, then go around gathering the best of the stuff into 4 of the big backpacks before going down a level. (Lots of armor, some of the better short range weapons, a couple engines, and some spare legs/wheels/wings are sure nice) Then try to get to an edge or corner or slightly defendable area, drop most of the spares and backpacks and get into combat configuration. Then make brief thrusts out of the area, knowing you have a nice stockpile to fall back on if you have to.
Eventually I had trouble with this because of area-damage weapons blowing up my precious stash, although at least some of the problem was me not being careful *enough* using the longest range sensors to scout enemies, not using optimum configs to take 'em out fastest, and not retreating quick enough when in trouble. At some point it does seem necessary to switch to speeding through, but I think with careful play that would be only the last 3-4 levels. And yea you do have to be ready to switch to other configs - an Uberconfig is fun while it lasts, but parts WILL get shot up and you're in trouble if you're not ready with a plan B.
The downside is it takes excruciatingly long, once I get back in the swing I will probably limit it to the middle levels, only picking up "enough" spares before going down on the easier levels...