I'm still using 10.6.8 Snow Leopard, so I doubt that were using the same version of Time Machine. Time Machine does not have versioned backups. When I need to recover a file, I tell Retrospect to retrieve that file over a specific date range. It will list all the versions (with backup date and time appended to the original file name) and give me the option to retrieve some or all of them. I can examine each file and see which one is best. With Time Machine, I have to manually retrieve the file from each backup in the desired date range. Each retrieval is a pain because I must respond to the Keep Original, Keep Both, Replace dialog box. I waste more time because many of the files may be identical, but I won't know it. The file names are the same, so I would have to rename them to work with them. These are not characteristics of a true versioned backup application.
The Time Machine version I have can do a complete restore of my bootable drive, so it has to back up almost everything. When the disk with the Time Machine backup starts getting full, Time Machine dumps older backups. It doesn't ask. I cannot change the saving pattern of the number of hourly, daily, weekly, or monthly backups retained by TM. I cannot specify the contents of Time Machine backups as I can with Retrospect. For example, I tell Retrospect to back up my Documents folder and any file or folder I tag as red. I add the Pictures folder, the Preferences folder, the Keychain folder, some items in the Application Support folder, and my eMail folder. Can Time Machine be that specific? Each Retrospect backup takes much less disk space than a Time Machine backup.
Time Machine is a poor hybrid of a while-you-work backup app, a versioned backup app, and a clone backup app. It should have stuck with the first. I would love to have an app that saves open documents and changed files every five or ten minutes. It would be even better if it could capture keystrokes (organized by document) so you can go back more than the twenty or so undo steps that most apps allow. Well, I can dream.