The important thing for me is whether your MP is a good constituency MP. I have lived in different areas and have had good constituency MPs from both the main parties. This is why I continue to vote. My current MP is not someone I whose parliamentary activities I admire but is generally accepted to be an excellent constituency MP and I have friends who have personal experience of this ( despite their political leanings being to the other main party ). Therefore, when there seems little to admire in either main party, this person would get my vote.