Anecdotal evidence suggests the rate of upgrade success isn't as great for anybody now as it was in 2002-03, esp. Silvers, but things will vary by route, day and time of day.

I wouldn't expect to get into the front cabin regularly on weekday departures to the west coast, for example.

But some status is better than no status. The main benefit to SEs, I think, is the ability to click on the P seats in coach and board early (right after F pax). If nothing else you should never have to sit further aft than the third or fourth row of coach.