Is this roughly the same animal here or am I saddly disallusioned about the Diana? Is the Diana worth the investment or will it never be as good as a Prosport or Theoben Elimonator?
Are there other options I'm over looking?
I don't think that you should sink any money into your Diana. The ProSport or Eliminator sound good. Also consider the RX-2 which is a really solid gun for a reasonable price.
An upgrade stock will not help kill the critters any deader, and from what I have seen the ProSport and Eliminator already come with nice stocks. The RX-2 stock is good and really solid but may require a mother to love (some people love it but other's don't).