To be able to delete a send in 2 clicks without having to go into the drop down and select delete would be great
 

To be able to rename the VSTs and have them stick would be nice

To have a cascaded sends destination menu would be great. Like, hardware outputs, buses, sidechain inputs, aux tracks, patchpoints. After having inserted a bunch of buses and sc capable plugs it gets pretty cumbersome to scroll to select what I need. Even just my 18 outputs interface (and then mono and stereo) makes a sizable list.

Noel Borthwick [Cakewalk]
I'm curious what tasks you perform in plugin manager and why it's important to you. It's a tool that one normally only uses to create new layouts.

Something I think would really improve this, would be an automatically populated "new" category in custom layouts. So when installing a new plugin, it by default appears in "new" in the insert plugin right click menu, until you chose to manually put it somewhere.
 
Another obvious improvement would be saving an updated layout. At the moment, you go in, add your new plugin to your layout, press the save button, get a "this file already exists, replace y/n" menu and so on. This could all be made a lot snappier and use far fewer clicks.

My three bucks worth:

1) MIDI sends (No I don't want to use Hubi's Loopback MIDI Driver)
2) A decent routing diagram.
3) Better multiple controller handling in PRV (no - don't tell me to use automation - CC's can be more flexible)
4) Horizontally scalable automation curves
5) Automation curves clips

Ok, that's five bucks

promidi
My three bucks worth:
2) A decent routing diagram.
Ok, that's five bucks

OK, I vote +1 for a routing diagram :-)

Noel Borthwick [Cakewalk]
I'm curious what tasks you perform in plugin manager and why it's important to you. It's a tool that one normally only uses to create new layouts.

If you had 2000+ plugins you'd be running the manager a lot more often too.  Seriously though, a great number of plugins have issues with VST3, which require disabling the VST3 version.  It's also fairly common for updates to have issues and require figuring out why a plugin isn't showing up inside Sonar - while the plugin manager is weak it's still faster than regedit.  I also have to rename a number of NI plugins since there is no way to tell which version is which with some of the Kontakt plugins.  Sonar loves to lose the renames so I end up with 3 copies of Kontakt 5 instead of the more detailed name with the number of output channels.
 
The layout controls I would use all the time if they scaled up to handle the number of plugins I have. I bought the MenuMagic app to try and help, but it's not really up to handling that many plugins either.
 
Recent releases of Sonar have also begun doing a crazy enumerating all my plugin registry entries the first time I right click on a audio or MIDI clip.  At first I thought Sonar was hung, eventually it finishes walking the entire registry and brings up the right click menu.  Only does it the first time after Sonar is started.  I think this "feature" was added around January.  Not sure it's 100% related to the Plugin Manager but it is really annoying.  Only figured out it was plugin scanning because I ran Sysinternals Procmon and watched it enumerate every single plugin on the first right click on a clip.
 
I still have DX 32-bit plugins (using a 32-64 wrapper) that I bought in the 90's installed and working.  I pretty much refuse to give up any software lightly.  I get the impression no one at Cakewalk has ever used Sonar with more than a few dozen plugins.
 

Thanks for the update. We'll look into your reports.
 
FYI: We have about 4000 plugins installed on our test machine. I have close to 1400 plugins on my work machine (with waves plugins installed)

Oh, I just thought of another one (The plugin manager discussion reminded me)

Is it possible for the "add track" button to have an option to use the synth plugin layout as defined by the plugin manager rather than list plugin by manufacturer?  It must be bedlam for you guys who have 2549 plugins to try find the one your after using the "add track" button in it current format.

You can't really use the add track button with that many plugins really.  I just use the Plugin Browser window.  Its filter search is quick and easy. 
 
Other places in Sonar with a popup menu listing plugins are also equally worthless.  The Plus button in the Synth panel has a greyed out list of instruments (which seems to be related to the number of plugins at least for me, see this post for details and even steps to reproduce it http://forum.cakewalk.com/FindPost/3365094 ).  Oddly enough the Insert->Soft Synth menu item does work but the popup menu it generates is epic and unusable.
 
The original post wasn't about bugs though, but rather areas of Sonar that are long in the tooth.  I'd argue that the Cal language also needs to be either brought up to snuff or a more modern and complete scripting language, like Lua, added.  There are so many things I'd love to be able to do in Sonar that I can't without a better scripting system.