I use Duggal for E-6, rollfilm and LF, and I think they've maintained standards pretty well.
For C-41, you have to be specific about requesting optical prints and proof sheets, if you want them. I realized this when I got some proof sheets and was surprised at how sharp they were for proofs made with the negs in file pages (the page border was visible), and then I checked with a loupe and realized they were scans output to RA-4, meaning they were sharpened.
I really prefer contact sheets to be contact sheets, with emulsion-to-emulsion contact so I can judge sharpness from the proof, without having to check the neg.
LTI's website is http://lti-lightside.com/lti-gallery.html