I got Browseback with a bundle last year, and dropped using it soon after I tried to make it part of my daily workflow. With 1.5 I decided I'd try it again...

As with many others who've commented, Browseback, while a great idea in theory takes up a great deal of CPU and memory, especially while it's scanning in the background. While trying to adjust the preferences, it's crashed on me several times. However, what irks me the most about Browseback is that the options in the preferences window for how much disk space its cache should take up, how long it should retain its history, and from what date it should start importing simply aren't respected at all by Browseback. They'd might as well not be there at all.

After setting it to use 50 MB of disk space, I've consistently seen its disk cache balloon to over three times that, thanks to entries dating back from December 2007 which it won't delete even though I told it to only keep entries for two days, starting from yesterday. I ended up just deleting it manually. This was an issue I had with it when I started using it at 1.4 and it's still behaviour I see now in 1.5.