I always keep my starter on my team. I just never liked the idea of not using my starter Pokemon. It's the Pokemon that begins the journey with me and that makes it special to me. There are times where it's rather difficult to use it because of how it is in battle, like with Serperior in White, but I wouldn't box it because of cases like that. I'd just try to work with it the best that I can and have other members of my team to help cover its weaknesses as well.