Tokudai's post is excellent info and I would like to add one thing, which is that in the case of a from-seed plant, and this is very noticeable in F1 hybrids, you will see unusually vigorous growth.
I have heard it suggested that the most desirable mother plants are actually from-seed plants, but no one has yet given me a solid reason why that is the case; I mean, yeah, if you clone a mother shoddily and stress her, it's not good, but an experienced grower shouldnb't have that problem... hmm...

Weedhound- hey you just hit 1000 posts, cool! Once clones are rooted, they are just as hardy as a seedling with the same mass of roots... but before they get roots, yeah, they are pretty delicate.