Well, in terms of the 6th and 7th rounders, its a mixed bag...
1. 7th rounders have basically no shot of contributing. At least, based on historical data from this organization. Michael Campanaro may be the best 7th round pick in Ravens history. They've done better with UDFA's, like a James Hurst, then they've done with 7th round picks.
So there's no way the Ravens can take any player in the 7th and expect him to be anything more than a long shot, long term, development project.
2. 6th rounders, historically, weren't a ton better. There were some solid depth players and contributors, but it's only been in the last 5-10 years where we've had some "hits".
If you start from 2013,
Ryan Jensen - good player, but took several years to develop into one. Only really got like 1.5 good years out of him
Keith Wenning
Darren Waller - outstanding player... for another team
Maurice Canady
Keenan Reynolds
Chuck Clark - good player
Bradley Bozeman - good player
Greg Senat
Deshon Elliott
Trace McSorley
James Proche
So there's certainly some guys to like in there, but a lot of these guys never got or even earned opportunities for starting jobs, and likely never will. Several are out of the league entirely, and several others may soon be.