Nope never and I don't think that its something that you should do
I have only tossed my starter once- in Black. I used Serperior until it was level 45, then ditched it in favour of Axew because I found it hard to use.
This is Bidoof. Many people loathe it with their lives. If you are of the few people who love this little beaver, put this in your sig. Started by Earth Wolf-Howl (formerly Warrior Scolipede)
Friend Safari: Sunkern, Sawsbuck, Maractus
I have claimed Pyroar!
I've done it quite a few times. Sometimes I don't feel that they work well within the team and that there is often a better alternative.
Extended White 2 Team
White 2 Friend Code: 2624 0604 4045