Both have pros and cons but I'd say skywest. At edv you'll be based in lga/JFK your first 6ish months on reserve and then when you come to dtw you'll be on reserve an additional 6 months.

Guy I just talked to at endeavor flew just 200 hours his first year there. Tons of fos there have the time to upgrade but can't and it's pushing 3 years. The delta interview is nice but you have wait an additional 18 months after your ~3 year upgrade. The time to go to endeavor was '16-17.

At skywest you'll get dtw off the bat maybe a month or 2 of reserve and building time a lot quicker. Upgrade will be as soon as you have the mins.