I bought heirloom seeds. This is only my first time.
Most of them are highly susceptible to damage,
infestation but they're very hardy despite everything.
When I started out my intention was to avoid genetically
modified foods. I didn't have a clue that hybrids were
good plants, otherwise, where farmers have connected the
breeding of one sturdy or resistant plant with another.
Now I know that's perfectly fine. They're not "mutants"
like GMO plants which may have foreign life-forms installed
in their genetic make-up. Will love to hear some more speak
of their experiences with this.

I wouldn't want to use GMO plants, that's for sure. One reason I like to use open pollinated plants, even on vegetables that I'm not likely to save seeds to, is that if I fall in love with a variety, I know that I have the option of saving seed. With hybrids, you have to buy seed from a seed company. I've seen people very disappointed when their favorite variety of something is no longer available.
I'm also learning that it's much easier than I originally thought to save seeds from most things, like lettuce and other everyday veggies. I'm letting my radishes form pods and will be collecting seeds soon. My only problem is that I usually have so many varieties growing that crossing on many things is a problem. But, I will save squash seeds from my favorite squash after my summer squash die out, since the winter squash are on the vine longer, anyway. Or, just hand pollinate and bag a few blossoms, which is really very easy with squash and melons.