I have an Innova and I do pantos on many of my quilts. I like the themes of my pantos. I have found several that I use for Quilts of Valor. No one has ever had an issue with the finished quilt. I do quilting for myself, my family, gifts, and Quilts of Valor. If you are doing Quilts of Valor or any comfort/charity quilts, they are always appreciated by the recipients, because of the care and love put into them, not because they are super award winning quilts.
As for custom quilting comment, you need to ask whether it was truly custom quilting (of which there are many wonderful custom quilters), or was it a computerized quilting program where they selected a pattern and it was loaded into a system? Also, who said they would prefer "custom quilting"? You have to take the comment's source into consideration.
It is true that for true custom quilting there are levels of skill. There are many talented custom quilters out there, but there is still a top rung for competition level quilting, such as Karen McTavish, Marilyn Badger, and others.
If you want to practice free motion, I agree with Peckish. Make muslin practice pieces that you can turn into pet beds or bind the piece to save as samples about doing a particular quilt design.
You should be proud of your quilts. Doing a panto is still hard work, because you still have to do the work of running the machine. If you want to expand yourself into doing free motion, take some classes, but do not feel lesser if you find pantos work best for you, especially if you are doing a lot of quilts. Pantos provide a good variety without having to come up with a new or different idea by yourself. It still takes skill to follow the panto without too many jiggles. It only makes you human.
