My five star rating is actually for John Angell James's lengthy introduction, which is brilliant and, I would say, a must-read for every minister, full packed full of wisdom and advice and food for thought. It stands alone and doesn't need to be read in conjunction with Spencer's Sketches.
Spencer's Sketches themselves didn't impress me so much, and I would perhaps only give them four stars. They started out well enough, and I did really enjoy some of them. Maybe the novelty just wore off and they began to feel very same-ish. That being said, the whole volume was engaging and interesting, but I was just glad I was reading this edition, where only a selection of the original Sketches was presented. This edition contained 42 sketches in total - 23 selected from the first series, 19 from the second.
This edition greatly benefited by john Angell James's sparse but judicious editorial comments (in the form of footnotes) which didn't alter Spencer's own words, but added a few observations or cautions where necessary.
There is also a brief sketch of Spencer by Rev. Dr. Spring. Spencer seems to come out of this volume very favourably with all his wisdom and discernment regarding revivals and revivalism Overall a commendable and potentially useful book.
If it were shorter I rather wonder whether it wouldn't be a good evangelistic tool. Some of the narratives might stand alone as tracts to get non-Christians interested in Christianity. And church-goers who have never made a profession of faith might find sketches in here which paint their own cases accurately, and it could be just what they require to get them past whatever stumbling blocks are in their way.