I had the table with my 6600 ... and when I switched machines, it was a must have, if I was to have a new machine. The 8900 Janome table is the same, except for the insert being added, to allow you access to the free arm.
It's sturdy, and when you take your machine out, very easy to move around. No need to have the casters. You can slide it easy enough with the machine in if you're moving it just a short distance, though safer to remove the machine!
Only drawback ... virtually no storage!
Yes, I highly recommend it!
When I purchased my machine, it was part of the package deal ... I probably would not have paid the price at the time, if it was an add-on cost. Though once I had it, I saw the good value in it!