With 8 draft picks this year, CJ Spillman made the 53 man-roster as the latest UDFA. AJ Smith has had at least 1 UDFA make the team since '03 and that player usually lasts 2 years on the squad which is pretty impressive.
'03-Dielman, Gates, Cooper, Osgood, Cesaire
'04-Floyd, Welker(I know he was cut, but I'll give AJ credit for finding him)
'06-Gregory, Gordon, Tucker
If the UDFA makes the team, AJ usually gets it right and that player should contribute something for the year. Spillman did make some coverage mistakes in the pre-season but he was a legit hitter and someone who was around the football. Special teams is were he will make his mark but I see a bright future for the kid.