my personal opinion....completely depends on how long you veg the plant. You can veg a plant to the size that you want and then put it into flower. Just keep in mind, that out of ten seeds, you COULD get anywhere from 1 - 10 female plants, where as with clones you have 10 - 10 chance of having a female since it is identical to the one you took it from. So it boils down to just a couple of things, 1) do you want to worry about sexing the plant 2) does the veg time really matter all that much to you? 3) do you really care how many of your plants will end up being male?

Now with that being said, if your only choice is to order seeds and then grow your kinda stuck with what you get, but if you get to know "someone" REALLY well, i'm sure they could get you a female plant and you can take off from there. Its all a personal choice.