There are advanced programs that allow for pitch, yaw and roll adjustments which help to eliminate odd distortions a due to tripods and fixtures not being perfectly level. They require more user knowledge and skills to maximize their effectiveness versus the throw the pictures in and hopefully the program will fixe everything software. Some of these consumer programs are pretty good but if you want to go beyond the canned and simple stitching programs you will need to step into the learning curve of more advanced programs. The one in particular I like is PTA written by Max Lyons. Google Max Lyons and you might find some very interesting and useful information. His forum has slowed down in activity the last couple years but there are some extremely talented and helpful people still contributing. Some of Max's personal work is phenomenal.

JT,
I think you have it right already with the overlap.
I often do stitched panos.
I used to overlap less.
Now I overlap 50%.
I see no evidence that this causes softness at all.
As a matter of fact I think it provides much much better stitches.
Think about it. The more overlap, then the more data points the software can find to verify and accurately join the stitch.

I did a 270 degree 11 shot stitch recently with a 50mm lens.
It stitched in an S bend and when I cropped I lost about 20% in height.
The next week my levelling base for the bottom of my ball head arrived.
I went back to the same spot and paid proper attention to my shot taking set up, and made sure I had things level for the full rotation. It stitched perfectly straight with not a noticeable join, all the way around and I lost virtually nothing in height.