Well, the workaround that I found simply involved shutting off Time Machine and using the "Back Up Now" item once a day to back up to the Time Capsule. I couldn't find any other solution here. My guess (and it's only a guess) is that the reason for the slowdown is not the transfer speed (gigabit Ethernet) but the possibility the Time Machine is doing a lot of work comparing snapshots and deciding which files to backup. However, that's just a guess. Be that as it may, as I noted in my original question, left to its own devices, it can take 30-45 minutes to back up a relatively small amount of data between preparation, backup, and closing. Then it sits idle for 15 minutes and starts the process again. Maybe there is no solution. Maybe that's the way it's designed to work. Also, I don't have much on my internal hard drive, maybe 25 GB all told of a 500 GB drive. So, it's not like I'm backing up massive amounts of data at any given time. From hour to hour, maybe 500 MB get backed up, and that is most likely because a lot of system files have been touched in that time period.
Many thanks for the quick reply...wherever you may be.
It certainly seems we both have the same dilemma.
I will hunt a little more for a solution, perhaps even call those good folk at AppleCare...if I make any ground then I will get back to you,
Otherwise, like yourself, it will be manual backups and be done with it.
Good night and cheers.