Yes, as Robin points out fast Newts need good stiffness around the focuser and this requirement goes up exponentially in proportion to the camera weight attached and increase in photographic speed.
If you are using a small web cam I imagine the stock focuser and tube might be fine but most wanting a wide field fast scope are usually interested in using something bigger and usually including filter wheels, electric focusers and off axis guiders etc all of which add significant weight at 90deg to the tube and impart all sorts of torsional and twisting forces. As you step up in camera size and add on accessories the need for extra stiffening really goes up particularly as chip size increases - the larger the chip the more obvious any problems become.
My scope has attempted to address much of the potential problems with a fast Newtonian and you could look to modify a new cheaper OTA in similar ways if you like:
Tube rings to support the focuser base
Strong rear tube stiffening
Solid internal tube stiffening around the focuser and thick one piece spider
Direct threaded adapters where possible and a robust electronic focuser
Having good solid well spaced tube rings held together top
and bottom (as in the first link above) is a very good idea too and even more seperated than I have would be better.
A carbon fibre tube is stiff but also has lower expansion qualities that will reduce the need for refocusing during the night, at F3.8 I have had no issues with refocusing over several hours.
Ensuring that the main mirror is held properly with in the main cell is very important here too, all the retaining devices ie side supports and retaining clips, must be physically touching the mirror so it can not move at all but not applying any net force on the mirror (or else astigmatism is possible).
In a nut shell, anything that improves the ability of the OTA to resist bending, flexing and twisting forces and careful attention to stabilising the main and secondary mirrors will be needed.
Then if you are going to use piggyback guiding the guide scope and camera need to be held hard and fast to the OTA or mount (this is one area I need to improve actually).
If all this is done then you can really take advantage of the extra aperture and speed a scope like this will provide over the more popular and trouble free but smaller and usually slower APO alternatives or the field and speed restricting RC and similar scopes.
Hope that helps
Mike