Per the conversation with Jared B. last night, 1and1 dedicated servers are true dedicated servers. Supposedly they do not use a VPS.
[UPDATE]

I emailed them last night:

I am having some performance issues in comparison to a similar box that I have as a dev server…I am trying to figure out why.
Now when I joined 1and1 it was expressed to me that my dedicated server was a “true’ dedicated server. Meaning it was my own box. Is this the case? Or are you running Virtual Private Servers for all root/dedicated plans?

Please respond ASAP because I have the feeling I have been mislead to a service you have but you really don’t offer.

Thank you.
Daniel Cameron

There first response:

Thank you for contacting 1&1

As I have checked your account you have a Root Server it means that if you have a dedicated server you have the full administration and control to it. You can install anything but you are responsible of doing it so.

If you have any further questions do not hesitate to contact us.

–
Sincerely,
Lorenita Rule
Technical Support
1&1 Internet Inc

Gosh they are stupid, so I replied:

That is not what I asked. Do I have my own box? Is any other person using the same system as me? Is this a virtual private server?

How can I ask this any different?

I am about to cancel my service if you don’t get back to me with a real answer.

Their reply:

Thank you for contacting 1&1

Yes, the dedicated server option provides you with your own server and your own box. This is solely assigned to you.
If you have any further questions do not hesitate to contact us.

WOW, I can’t believe it. So of course I had to ask again.

Sorry for me being so skeptical.

I am writing an online review of your dedicated server plans and I want to make sure that your dedicated servers are true dedicated servers. Meaning all dedicated plans have only one user per computer/server/box. And that you are not running Virtual Private Servers.

Please respond ASAP.

Thank you.
Daniel Cameron

And their response:

Dear Daniel Cameron,

Thank you for contacting 1&1

Yes, the 1and1 dedicated server is only for one user per computer/server/box.

If you have any further questions do not hesitate to contact us.

–
Sincerely,
Josephine Gamotin
Technical Support
1&1 Internet Inc

[UPDATE]

It’s true. I am right and Jared is WRONG. Finally, so Jared when do you want to start using your new plesk account.