IMO PPBs aren't so unbalanced as might seem... still, I like to play with tech cost set to high - I suppose that at low cost they're probably too easy to obtain.
The only tech I found really unbalanced was the allegiance subverter (before it was changed not to affect ships with master computers) - there was *no* way to defend from it, at most you could reduce the losses.
This said... my worst game ever... well, it was a very quick two player game. I had prepared a large fleet or two and was about to declare war on him when his home system's star blew up and destroyed most of his empire...
It was quite disappointing... my first thought was "I've played so far for nothing".
Still, for some weird reasons, I enjoy playing (almost-)doomed empires, resisting to the Last... which is nice, since in most games I regularly get outnumbered, outgunned and outeverythinged
