HD Upgrades possible in the popular models?

[Stoofa]

I am currently doing my head in trying to decide which unit to purchase.
Looking at the 4 popular models:

Sony HX510s
Pioneer DVR-530H
Toshiba RD-XS34
Panasonic DVR-530H

I was almost decided on the Toshiba - liked the idea of the 160GB HD over the two 80GB models and felt I didn't mind losing the dual-layer burning.
It also seems to be the cheapest of the four models.
However I've now read at least one thread where people have said the fan noise on the Toshiba is a little loud.
So now I'm leaning towards the Pioneer - still get the 160GB HD although those who are holding stock on the Pioneer are selling for around £40 more than the Toshiba would cost.

Are the HD's "unofficially" upgradeable on any of these popular models?
Done some very basic searching and not come up with anything other than the Sky+ box upgrades.
I'm looking at the pro's & con's of the 4 models - can see some of each on each model just cannot make up my mind!
An upgradeable HD would certainly be considered a "pro".

Godammit...which one should I buy...

[dicky]

[Mod comment - edited as I've deleted the nonsense answer above !]


No there is no way to upgrade the HD on these models.

Regards