Associating Brown with Ludlum is an insult to Ludlum. I'm sensitive there only because he's one of my favorite authors. Eric Lustbader did an excellent job carrying on in the Bourne series (Lustbader has a better grip on describing physical confrontations).
I can see suggesting Eco for the mysteries in those books but you're suggesting a double-diamond downhill run to someone who skies on the bunny slopes. A satisfied Dan Brown reader would get badly hurt. Oh, I did read and mostly enjoy Dan's books but they are fodder. I have low-brow taste.