
I had never heard of Helen Mirren before I watched this series, and I've been a fan of hers ever since. Looking back now, I can see why Prime Suspect got so big, and why the San Francisco Chronicle called Detective Jane Tennison "perhaps the greatest role and performance of a female police detective, ever."
Mirren is utterly assured as the cop who wants to prove herself to a slew of sexist colleagues, but her performance is nuanced enough to show us her moments of vulnerability--moments that never happen in front of the men she must lead. I still love this series after 20 years; it is a testament to the fact that good writing and good acting produce a chemistry that lasts.
I fear the new cast has impossibly large shoes to fill, and the comparisons to Mirren's version will be inevitable. In any case, I highly recommend a look back at the original series, which you will want to plow through with obsessive speed (or at least I did). :)