I don't use the right button so much, but I'm not saying it is better (or worse..)
One advantage is that you can ROTATE and ZOOM with only one hand. This is a small but significant advantage when you either want to sit back and ponder your model... but also if you use your other hand for inputting numbers on the keypad (I'm left handed...) or other hotkeys.
At times I do accidentally change the perspective, but it's not so hard to get back, and maybe I have a good mouse so it doesn't happen.
This disadvantage is reduced or cancelled out by the possibility of activating the radial menu if you decide to use the RMB and don't quite get the SHIFT or CTRL button pressed on time. This may be made worse by having a short delay time setting on the radial manual too.
Also, you can start a view change with the MMB and then add either SHIFT or CTRL without releasing the MMB. As far as I know, you have to first press SHIFT or CTRL and then RMB if you want to change view. Subtle differences, but MMB requires less mental pre-planning IMHO..
I made this complaint to my reseller when ST first came out. They laughed and asked why would I do that. I don't have a space ball and don't want one either. I use Control & Shift and have since I started using SE at version 7. Now the dam radial menu messes up my flow. I have since learned to set the radial menu as shown below, so it basically turns it off, much preferred. @Cek There's no way to turn perspective off, I've just learned to use the RMB or deal with the perspective annoyance. Who uses perspective anyways?
When we have been working in a certain way for Yeaaaaars, you can't easily change that because of one glitch we ain't using.
How about adding an option to disable completely the perspective view?
In my 15+years workin' with Solid Edge, I NEVER used this view, and find this useless.