I had the same experience with prints from slides, disappointing results,
dull colors, no comparison to the slides. It was the same with every local
lab I tried, digital or conventional process.
Then I got this tip to try Overlake Photo in Bellevue.
http://www.overlakephoto.com/main.html
I had a few 5 x 7 test prints made from slides recently.
The results were "awesome". The high gloss prints are as vibrant as
the slides themselves. Totally professional results.
The prints were on Agfa paper, but don't know if they use the
same Agfa D-lab that Bruce mentioned previously.
One complaint that I have was the edges of the slides were
cropped all the way around, which unfortunately affected the composition
in a couple cases. Haven't dealt with that yet.
Guess I'll have to contact them about that sometime to make sure
it doesn't happen on a larger more costly enlargement.
Or is that common that slides to prints process crop the edges?
Harald