In my opinion, Bwin is not a good sportsbook. If you win they will give you very low stake limit. Moreover for US sports they have very low lines. In addition, their web is quite slow. On the other hand, no problems with withdrawing and wide range of opportunities especially on soccer (and also many live betting soccer events are avalaible). In conclusion, for someone who takes betting seriously, bwin is not a good choice because of the low limits...but I wouldnt be afraid of security.
PS. I am sorry for my bad english.