Well, it seems like many of these first round OL draft choices have actually stayed for a significant time:
Stan Brock, T: drafted in 1980; played with Saints until 1992. He finished his career with the San Diego Chargers from 1993 to 1995. [12 year career with Saints]
Steve Korte, G: drafted in 1983; played with Saints until 1990 [8 year career with Saints]
Jim Dombrowski, T; drafted in 1986; played with Saints until 1996 (career ended with knee injury) [11 year career with Saints]
Willie Roaf, T; drafted in 1993; played with Saints until 2002; finished his career with the KC Chiefs from 2002-2005 [10 year career with Saints]
here's where that revolving door opens, however....
Chris Naeole, G; drafted in 1997; played with Saints until 2001; currently with Jacksonville Jaguars [5 year career with Saints]
Kyle Turley, G; drafted in 1998; played with Saints until 2002; played 2 years with the St. Louis Rams and then joined the KC Chiefs in 2006 [5 year career with Saints]
Jammal Brown, T; drafted in 2005; still with the Saints after 3 seasons.
Even Naeole, who was slow to really do well with us, went on to continue a solid career with Jacksonville; Turley also proved that he could play for several years. We gave up on those two guys but that's no reflection on their overall NFL careers. 10+ years out of a solid OL is golden, and looking at our history, drafting a good OL in the first round is rarely a bad idea...as long as we keep them! I would hope that Loomis & co. would do a better job of keeping that sort of talent than we have in the past; JMO.