Hey, folks,
To the OP: In my wasteland, at least, humans are a very viable choice.
First off, I've modeled my MF campaign on Fallout. This, so far has required very little tweaking - mainly, just adding monsters from the Fallout series (many of which are either represented already, or can be easily engineered based on existing MF creatures). The main thing I've changed is the availability of conventional firearms - while your average tribal village will have, at best, a few black powder rifles for hunting and defense, firearms are available for purchase in more cosmopolitan/well-travelled settlements. As such, initiative is pretty important - with all those guns around, getting the first shot is kind of a big deal.
So I've introduced a houserule: Intelligence grants an initiative bonus (or penalty) equivalent the same level of Dexterity, and the total modifer (positive or negative) is halved to arrive at the effective modifier. This makes the PSH's Int bonus very attractive. In addition, besides weapons, a lot of the missions my players come across involve use of the technology skill, even in mundane uses. For example: Last session, the characters had to fix the village still. This required some specialized pipe fixtures - which just happened to be flush valves from pre-fall urinals.
They were available at a ruined elementary school, but required a complexity 1 tech roll to salvage. Even cutting the time in half for a simple task, the party ended up spending 2 hours stripping these parts (and fighting off creature encounters the entire time).
Beyond that, I make liberal use of reaction rolls for in-town interactions - and most towns in my wasteland are populated by PSHs, in large part. So again, the humies have a tangible advantage.
All in all, I find PSHs very survivable in my game - I doubt the party would want to try and get by without at least one.
- DYA