pimpsticky, your description of the pre-cooked shrimp is how I would describe overcooked shrimp.
I agree with Eric for the most part. I buy EZ-peel shrimp for 4.99/lb every week and it has been thawed. I never really reasoned it out that way before...I'm probably going to start buying the frozen stuff instead since they've both been frozen anyway.
There is always a "fresh catch" and if it's reasonably priced & suits my palate, then I'll buy that too. Certain fishes seem to hold up better than others during the freezing process.
I hate pre-seasoned stuff though! YUCK!