Question: I designed a pictures grid in sketch, and wanted to export the hole grid as one jpg or png, and then add it to my website. I am wondering if the quality of the jpg or png would be as good as photoshop? Is there specific settings I should use? What about color management?

Answer: 
Sketch is designed especially for the web/mobile UI design. Therefore, unlike photoshop (older versions) Sketch is optimizing PNG and JPG formats successfully. You don't need to worry about lots of quailty settings as in the photoshop at Sketch. [Here is a tutorial for that](http://webdesign.tutsplus.com/tutorials/understanding-sketchs-export-options--cms-22207)

Therefore, go for it!
The answer is no.
Photoshop JPG export is far superior to Sketch.
This is frustrating as I have to export from Sketch as PNGs. Then open in Photoshop and save the PNGs as JPGs from Photoshop.
(This is the case, even if I set a very high jpg export quality when exporting from Sketch). Photoshop's save-for-web creates higher quality jpgs yet with a smaller file size. This is most noticeable around things like logos or areas of flat colour.