Nordic Countries - Is the Helsinki card worth it?

It looks like it includes admission to a lot of museums (including Suomenlinna), as well as all public transit. But it's hard for me to tell whether it makes sense vs. just paying as I go.

Any opinions?

If you want to do a guided bus tour, then it is probably worth it. If you are not into such things, you need to use quite many of the other benefits to break even.

For comparison, the 1-7 day ticket prices for Helsinki area public transportation:
http://www.hsl.fi/EN/ticketsandfares/Pages/Dayticket.aspx

One zone covers Helsinki including the HSL Suomenlinna ferry. Most of the Suomenlinna island, including the fortifications is free public space, only the museums and such have fees.

IMO it is quite pricey, unless you are thinking of hitting every museum. I suggest buying the public transport ticket, and for the rest pay as you go.

As for Sveaborg , sorry Suomenlinna ;) , I think buying the guided tour (8€) and then walking around by yourself is a good option. That will take a few hours and not cost much.

I've been to Helsinki often with tourists (I work as a tour guide) and I like the place a lot but it's not really a city with great museums. The most unique sight is the Rock church, which is free. Otherwise walking around the market square and the ferry to Sveaborg are sufficient for those who have just a day there.