They are not all scams.
Four years ago I went through a debt consolidation for similar reasons: I had substantial debt (thanks to my now ex-husband) and a good credit I did not want to ruin. They set up a schedule for me and I was able to pay everything off in 2 years instead of 15. Except for a few very minor glitches everything went fine.
Most of my credtit cards reduced or eliminated interest and changed my due dates to coincide with when my consolidating company was sending them paymnets - this way I avoided late fees.
As for the effect on my credit: I had a total of 6 accounts consolidated. 3 of them were reported as being in debt consolidation (Sears and GM). Of the 3 credit bureaus, only one reported Sears and GM as a potentially negative item.
It is now 4 years later and my credit is rated as "very good" with a very high credit score.
So, for me, it was well worth it. And it saved my a lot of money in finance charges.
Just remember to investigate the consolidating company. Check if they are licensed in your state, if they have non-profit status and if there were any complaints filed against them.