Hey Man,
It would be tough to say what regional is "best" for schedules, that has so many variables from your seniority number, work rules, the amount of folks on reserve, etc. The best advice I could ever give someone going to work at an airline, especially a regional where you would most likely make a lot more money flying w/ the guard/reserves is live near your guard/reserve gig and if you have to commute, commute to your airline job. Rational being on your days off you can easily go in for locals/sims or other ground activities, while when you are at the airlines, when you are flying a trip you usually are flying away from your domicile for the most part, unless you are lucky enough to bid day trips (usually the more senior folks snag those, though it is airline dependent).
You are correct, USERRA will protect you from dropping trips and you can use that to your advantage, but if you want to maximize on both, the best way to do so is having your reserve/guard gig at your airline base, which I know very few places that have that. Where are you at guard guy @? Feel free to PM me if you have further questions.
Mongo