Time Machine performance?

Well define slow...

There are too many variables now. Did you try to back up to your machine's HD or did you use an external? If I am backing up 15 GB of data, then it might take a little longer, probably around 15 mins. Usually my back ups (after the initial of course) take 5 mins max and are about 100 MB to 700 MB in size. I think it works great. I have noticed that the larger the intervals are in between backups the longer it takes, as TM "cleans up" my external after each back up, so theres more to organize as the time between each gets bigger. I use it mostly as a back up then the whole see older versions of my folder feature but thats just me.

Hope that helps! I am using a 1 TB WDHD on a 2010 MBP running 10.7