So a little over a year ago I received an email from Chronos announcing this utility. I was hesitant about purchasing Spotlife, since I've had a love/hate (mostly hate) relationship with the company over the years, but since it looked to be something I could use I compared it to the competition.
It's been to long since I did the comparison (to Blotter, DateLine, and TimeWorks -- in the Similar Software above) to give any specific reasons for my choice, but I did end up choosing Spotlife over the others. It's a beautiful, if overpriced, app and even if it doesn't support editing of events it does exactly what I need: quickly display an overview of my calendar.
Buyer beware, however: you will find that support is spotty at best. Chronos has, in my opinion, the second-worst track record in customer support (after Nolobe, the developer of Interarchy); forum messages, support tickets, and email messages will go months without being answered. And, at the current time, the download link for Spotlife 1.0.8 is non-working (has been for 10 days).