Out of those 3 options, I would definitely ditch Ground regardless of how "nice" the new route is. Truth is, you'll be working just as hard at Ground as a UPS driver for half the wage (maybe less than half!).
Express for sure has its pros and cons though. What's the schedule for the FT position at Express? I wouldn't take any FT position that wasn't a regular morning/daytime route, but that's me. I work roughly 0700-1600 but we have some FT drivers who are 1300-2100 routes.
If you're young and don't mind the work, UPS will pay you much more short-term as well as long-term, but it will turn your joints to dust over time. Express pays less but the work can be way less taxing than what Ground or UPS would put you through. Also Express is going through a ton of changes and they're trying to cut OT as much as possible, but I've heard that line as long as I've been with FedEx.