We just returned from a 2 week venture to east coast and now DH is lobbying for us to take a 7 week tour, from Sinapore to Los Angeles, on the Regent...has anyone done this, and if so, what are the pros and cons....

Hello, don't know if you are still looking for replies after so long, but I have not used Fodor's forums before. Anyway... Yes I have gone around the world onboard a Regent ship. There are quite a few people active on cruise-oriented message boards who have. Here is a link to the blog we kept while onboard that cruise on Voyager.
http://westwardworldcircumnavigation200.blogspot.com/
But, I see you are looking at 7 weeks on Mariner. Here is a link to a blog we kept for 6 weeks on Mariner around South America last year.
http://circle-south-america-2008-aboard.blogspot.com/
As to your question of pros and cons... I don't see any real cons, all pros. The only things I would warn you about are that is a long stretch of sea days, I case you really hate sea days. But, they are on your way home (well, that is an assumption on my part!). I really prefer a cruise home, rather than a looong flight! So, maybe that is a pro. The only other con is that you are sailing mostly eastbound and the time changes are working against you. If you can ever take a cruise going westbound, you will enjoy it much more without losing an hour every day or so. If you have any specific questions, I'll try to help. Debbie