VST folders

Be careful with VST3 plugins. To date Sonar is the only program that has provided a choice for installation location, though by default it is the same path I've listed below.

Every other developer I have plugins from uses the default Program Files/common Files/VST3 folder without an option to change it.

All the advice on this forum has always been to keep Programs and Plugins on the same drive. It's not like sample data that gets read in and out of memory as the samples change. There's no advantage other than organisational. But which drive will you put them on? With samples? With Projects, by themselves?

I have close on a thousand plugins but they don't take up that much space comparatively. It's only sample libraries and projects that take significant amounts of space.

You probably don't have many DX plugins but they can't be moved around at will. Certain files during the installation process are entered in the registry. VST plugins are scanned by the host and registry entries created that way.
By default developers actually look for a system VST plugin folder which by many is considered as C:/Program Files/Steinberg/VSTPlugins. I use the path "C:/Program Files/VSTPlugins/ folders by developer" if you have plugins from a lot of different developers. By doing so, Sonar creates folders in the default plugin layout instead of one long continuous list which can easily get wieldy once you have a list comprising 39 or 40 plugins or more as in my case.
One other point. Not all developers give you a choice of where to put VST plugins of any sort and will insist on their own location. However I've found that when moved manually when updates are installed, most respect the new path.
When you encounter manufacturer folders within the C:/ Program Files tree these are usually for support files and often for .exe files if the plugin has a standalone version. The plugin dll is never located with those files so don't get it into your head to just move those folders thinking it's OK. It ain't. Except of course when the support files are manuals. There's lots more to learn but that should get you started. Maybe you know all that anyway, in which case don't be offended by me treating you like a complete newbie.

In addition to the good advice above, I suggest:
 
VST3:
Leave them to go under the 'standard' location.
 
Cakewalk (VST2):
Leave them under %CakeHome%([\vstplugins],[\x64\vstplugins]), as per default installation, for simplicity.
 
VST2 / 3rd Party:
Maintain 2 'top' directories - 64bit and 32bit (if using) ... because sometimes each variant has the same DLL name.
 
See my guide:
(written wrt Steam MC6T / Sonar X3 - but generic / transposable)
Shell's Probable Guide to VSTs - Location, Strategy and More