went through a lot of posts on this site.
Honeymoon planning: we would like
-sandy beaches,
-activities (snorkeling-hiking-tours-etc)
-nightlife ( i.e not secluded, not family type, kind of young&happrning).

we would have 12 days mid-july.

can someone with past experience compare point per point (esp. nigthlife) two tentative trips:

A/ Hawaii: Maui Kea Lani (8 nights) + Kauai ( 4 nights )

B/ Carribean:top contender would be 8 nights in St Maarten, 4 nights in St Barths.
or better carribean suggestion accepted too.


THANK IN ADVANCE TO YOU ALL

I've been to all the above places. If nightlife is a really big priority, Kauai and Wailea (Maui) are poor choices. St. Barth's has some nightlife but it's relatively subdued. St. Martin has a bit more.
Overall, of the 4 islands (for a honeymoon), I'd rate Kauai and Maui and SB as at least 8-9 on a scale of 1-10. I'd rate SM about a 3. I really didn't like it at all. Scrubby, very impoverished, crime is an issue. It's in no way in the same league as the other 3 islands.
You'll find a number of people who defend SM on the Caribbean board, but you'll be hard pressed to find anyone who will try to argue that SM is in the same league as SB for a honeymoon.

I would go with travleis on her 3 recomendation for St Martin. We've not been to St Barts or Hawaii, (Hawaii trip in less that 3 weeks!,) but did vacation on St Martin. The best beach we found on St Martin was the nude beach and the only people that were actually nude shouldn't have been. That's fine, but we'd never go back to St Martin.

We only did a cruise to the Caribbean but I wouldn't go back to St. Maarten for a vacation. A place I would consider returning to would be St. Thomas/St. John. We went to Maui for the first time last April and are about to return to Maui/Kauai this April. We could've gone anywhere we wanted so that should tell you something. If money isn't an issue I don't think you would regret going to Maui/Kauai.

Just a thought. If you want nice beaches and an active night life, why not Oahu? There is lots to do in Honolulu, discos, great restaurants. If you don't stay in the heart of Waikiki you can probably aviod little kids. But Oahu has the beautiful beaches, North Shore, Makapuu, Kahala, and also things to do, like movies, museums, Pearl Harbor, shopping (not just resort shopping), the Polonesian Cultural Center, and great eating. Twelve days would be a long time to spend on Maui, Kaui, IMO.

I like Heavens' thought. With 12 days you may even consider a few days in Maui for a change of experience, Kauai is gorgeous but maybe too quiet for you.