These kinds of titles are just pure fun - and if you approach them in this fashion then you can't go too far wrong. I really have to be 'in the mood' to read through a book of NPC's as most that are published (I'm thinking of D&D in particular) are dry catalogues of characters who are cooler than the PCs and achieve this 'coolness' by breaking established rules.
Not so here.
'Street Legends' is actually quite a good read. Whilst I have always enjoyed the BBS-esque format of Shadowrun books, this one diverges and instead presents each NPC from an in-character perspective. The interspersed fiction is welcomed, and is quite well-written. As with the 'Sixth World Almanac' the fiction is used to change gears and provide some points of differentiation for the reader.
As for the actual characters chosen, it is a very eclectic bunch - mostly drawn from the newest iteration of SR (there are some exceptions, but not many). Does this detract from your enjoyment? Certainly not. What I would like to see, though, is a Volume 2 focusing on the 'old school' runners from previous editions - that would be a very neat supplement. There are methods of brining any of the NPCs into a standard campaign, without them overpowering the plot and taking centre stage, but any GM worth their salt can do this. The only disappointment for me was that there didn't seem to be an even enough spread among the types of characters offered - I feel that Catalyst could have covered a greater range of meta-humans. The meta-humanity angle seemed to be a missed opportunity, especially given the current 'Shadowrun: Missions' plotline.
In summary, it is a well-written, fine addition to your shelf, virtual or otherwise. It is fun reading for any Shadowrun fan. Ultimately, your appreciation (and use) of this supplement will purely depend on what your intended use for the title is. The newly discounted price makes it somewhat more accessible (and worth the price of purchase) - I certainly would not have paid USD45.00 for this PDF title.
I'll finish with the same thought as I started - if you want something that is a bit of fun to read then certainly pick up this latest SR4 title.
[4 of 5 Stars!]