For a desker, it's a great life (Mrs. Crimson, who works at the same PM daily as me, is home at 4 p.m. every day).
For a sports guy, it's a great life in the summer (when there's nothing going on) and you can work normal hours. It's difficult when you have a newsroom culture where everyone is expected to chip in during the deadline cycle.
I try to keep my staff's sanity by having people work three nights a week, but usually no more. They can file their stuff in the AM.
Writing-wise, the best part about being a PM is that you have extra time to work on angles and finding more unique ways to tell a story. Most of the AMs in our area have firm 10:30 or 11 p.m. copy deadlines, which barely affords enough time postgame to get quotes and fit them into a running gamer. We usually have the luxury to develop a storyline and write the "game feature," which has really develloped my skill in event coverage. Developing that style will really help you at an AM, because your mind is almost forcibly trained to think and look for featury/analysis angles from games.
We have the luxury of being able to staff the local NFL and NBA team's home games, as well as the stuff at a really big racetrack in the major metro. Because I know the Major Metro Daily has that covered like a blanket and hits the streets 8 hours before we do, I have to work extra hard to give my readers something different.
Working at a PM has really helped my writing skill, but you still get to build some good deadline reporting skills.
The split shifts, though, royally suck. There are times -- especially during heavy preps weeks -- where you feel like you work around the clock.