I've already got 1st edition, but haven't got a guaranteed group to run, so not sure if the rules upgrade is worth it just for my reference.
To fix something of the worst of it, I houserule that all injury totals are location-based for the purposes of critical hits. That avoids the problem of a minor strike to the head causing it to explode after nearly hacking a limb off - are there any other tweaks needed to enhance 1st ed play, or is 2nd edition enough of an overhaul to merit a new purchase?