Does anyone know how to enlarge and reduce tracks in track view without having to drag it? Older versions of Cakewalk/Sonar had a widget you could click on.

In Sonar, select Track view> View > Auto Zoom.  This will allow the the track that you select to enlarge.  When you click on another track, the previous track will go back to normal height and now the newly selected track will now have the zoomed Focus.
 
The shortcut is  SHIFT+Z

Auto Zoom is one of my favorite features. 
 
One thing to note is that when you're in Auto Zoom mode, there are two things you can set on the fly:
 

1. When you change the height of the active track, any other track you click on to make active will take that  same height, and the previously active track will shrink to the unselected height (see below)
2. If you change the height of an unselected track, all unselected tracks will mirror that height until you change it again.

This makes the view extremely versatile! Modify as needed.

 
 

Awe man PioltGav,
 
The visual is much much better,  Nice. 

I mostly use CTRL + up/down arrow but it zooms all tracks at once. 

Note that if you enable Auto Track Zoom, you lose the ability to maximize the track by double-clicking on it. Double-clicking on a bus to maximize it still works even when ATZ is enabled, so I guess this is a bug.
 
Personally, I really liked ATZ for some time after it was introduced, then I started hating it over time and finally concluded that it's just a source of frustration for me and disabled it for good. Why so frustrating? Try clicking on the Mute, Solo or Record button of a non-current track first. You'll see that it only mutes/solos/arms the track as expected and does nothing else. Then, try clicking on the Automation Read/Write or Archive button, or try adjusting the Volume slider, Pan slider, etc. of a non-current track. Every time you do that, that non-current track becomes the current track and unnecessarily changes the heights of the tracks. When recording audio, I frequently archive/unarchive tracks, and this unwanted behavior was a PITA. 

I could be wrong, but maybe ATZ is enabled by default, and this button (which hides itself when ATZ is enabled) is what the OP was looking for.
 

icontakt
I could be wrong, but maybe ATZ is enabled by default, and this button (which hides itself when ATZ is enabled) is what the OP was looking for.
 

This is exactly what I was looking for in Platinum. I am a little old school and I miss it. Thanks icontakt!