I've never used any of those services either...
On a side note, last night, I decided to experiment with my new Drobo a bit. While I've had my first Drobo for about two months now, I never tried swapping out a drive with it. So, I decided to give it a shot with the new one. I had two 1TB drives in the top two slots and two 500GB drives in the bottom two slots. Then, I loaded it up with about 1.3TB worth of data. Then, I pulled one of the 500GB drives and replaced it with a 1TB drive. Everything worked out fine. It took about 9 hours to rebuild itself and all the data is fine.
One thing to note is that when you first pull out a drive, the Drobo and the Drobo Dashboard software needed about 2 minutes to pop an alert on the screen. Then, pop in your new drive. Just be patient and let it do its thing.