Having been at both airlines you can expect to sit ready reserve for 8 hours at the airport A LOT if you end up going to envoy. They even have ready reserve lines you could bid each month. When I was there they had 4 ready reserve periods every day with 2 pilots sitting ready for each. If one of them got called out the next reserve guy in line would get called in to replace the guy who was called out. ( happened to me a lot! Nothin like getting the phone call at 4 am to sit ready for 8 hours at 6....) Skywest doesn't utilize ready reserve nearly as much as envoy but we do have the "bucket" system which sucks!
In the end, I wouldn't select an airline based off of ready reserve or any reserve for that matter as now days it's short lived. I spent over 3 years on reserve at envoy but I doubt that's the case for someone new there now. In the end my reserve experience was a lot better at Skywest. Now days at envoy you'll most likely be pre assigned a 4am RAP on day one and extended over and over, sometimes into your days off. Reserve is usually short lived now days, unless your a jr captain in a super senior base....,,