works perfectly
I have owned this docking station for over a year and it has worked perfectly for me. No power problems. Yes nothing works when the power is off, but no problem for me. The only problem, it does not come with its own power supply and together (replicator and power supply) are very expensive.

Not very durable, poor warranty
I bought one of these new from the SonyStyle store in New York in November 2007. After only three months of use, it started to deliver power to the laptop erratically. If I jiggled the laptop on the docking station, it would eventually connect. Finally this fix stopped working and the port replicator failed to deliver any power to the laptop. Sony won't cover replacement or repair under the limited warranty. Now I have a $200 paperweight on my desk! I loved it while it worked, but can live without it and wish I hadn't wasted my money. I have had problems with Sony's service before...they make great products but you have to hope you don't have a problem as the after sales service is worthless...

Replicator Review
Sony VAIO VGP-PRTZ1 TZ Series Port Replicator

Good product but have a problem with power outage. When power is cut-off from the device, all attachments (add-on devices) fail to work.

It does the job.
The port replicator does its job. Compared to other port replicators I have used (such as by Dell), I have not found this one to be of high quality.

If I hibernate or sleep my computer before undocking it from the port, it enters a state where its battery is continuously on, but the machine cannot be revived and powered back up into Windows. A hard reboot is required.

The connection between the dock and the laptop feels flimsy, and the computer can wobble slightly while connected.

All in all, although the dock has a few bugs, it does its job just fine.