My opinion
Particle board cribs don't bother me at all if they aren't drop side. It's not like they are just going to fall apart - they are extremely sturdy and feel that way. Plus, I need to be able to move the thing to put on his bumper/new covers/ etc. so the lighter weight makes that easier. Jack has the Da Vinci and it feels very sturdy. It's great.
If I were you, I would probably use your old crib and bolt the dropside in place for good measure like Keri did. Most likely nothing bad would happen, but if it did, you have this thread to look back on and then you would feel pretty bad that you had concerns but didn't listen and now junior has a broken arm or whatever. jmo