For me the decision is pretty simple:
1) I'm sometimes using untrusted networks (e.g., Wifi)
2) Google offers an SSL encrypted interface
3) Bing doesn't
1) I'm sometimes using untrusted networks (e.g., Wifi)
2) Google offers an SSL encrypted interface
3) Bing doesn't
Only Semi-Related: Everyone who uses Google SSL should be aware of this: http://www.seofaststart.com/blog/ssl-search-referral-data