Done with standalone apps, one can use filters, which can improve the quality of the finished dvd, versus a one-click copy.
Using separate apps, and doing it right, can make a huge difference in quality, compared to VSO and similar apps.
It depends on your eyes (or those watching it). If you're happy with VSO, fine. I'm not, and prefer to take the time involved with other apps.
The larger the TV, the more quality one should retain.
Sure, VSO works great on a 20", but sucks big time on my 48".