Congratulations! I gave birth to my second daughter in Zug in September (the first was born in the US). We delivered at the Kantonspital, and it was fabulous! The facilities are brand new, so state of the art. The midwives were so great and patient and supportive. And the "Wochenbett" (post-natal) care was great. I don't have any experience with multiples, nor do I know anyone who does. But I am sure they would be great.
As to doctors, I was very satisfied with my doc - Dr. Regula Leuppi. She speaks English fluently. And although she normally doesn't take new patients, she will do so if the woman is pregnant (which is how I snuck in to her practice). She has a private practice downtown, but she is one of few doctors that also has privileges at the Kantonspital and delivers her patients there.
http://www.praxxis.ch/
Best of luck! And if you have any more questions, feel free to PM me.