No matter how slowly it takes, I'd much rather build up a good team with what the game gives me then send in Pokemon from another copy of the game. I used to not care, but now I find that hunting down five good Pokemon to use is half the fun of the games. (I always use my starter, no matter how bad the choices look)
My teams always have generational pokemon send over, but never the parents(original) since its just to easy, however using the babies and making them as strong or stronger then the parents is perfectly fine to me. I started this once I started playing Pokemon FireRed/LeafGreen since it was a new start but unlike gen 1 and 2 I could send over eggs/babies to the other games and generations.
Gen 3 might have started bad but after the gen 1 remakes it was smooth sailing for the series and many long time fans who left but then came back once Gamefreak apologized for their mistake.
"Always two there are, a master and an apprentice"
I've grown accustomed to trading over an entire team lately. Its always an evolving list but really there are just certain ones I like the look/feel of rather than what I'm being forced to have. Besides, some of the ones I do trade over I usually can get in the game, just not right away. And I always trade over eggs and raise them from lvl 1.
My current "dream team" looks like this:
Arcanine Luxray Lapras Braviary Escavalier Sandslash and Cinccino as a 6th alternate
They're not the strongest but they're the ones I like. And the fact that half of my list comes from Black/White is pretty good.
I like my team this run through. But I found one of them in the Dream World, deciding to link it up and give the minigame a run and going what the heck, some of these could be fun (I picked up Magikarp).
I always trade over the Pokemon I WANT to use at the start. I'd rather have fun with the things I want to use than to be forced to use what the game offers at the beginning. It's not like there's anything wrong with it. Or else they wouldn't allow trading so early or have level caps for obeying traded Pokemon.
My Gaming Collection http://backloggery.com/alanedgehead
Thing is that you may not want to use the offered pokemon ingame. After a while you just pick up an Archeops and OHKO most things in your way. It ruins the experience but I really can't have that much of an experience when I can't use what I like.