My other favourite sportive, the Tour of Flanders has got a bit out of hand in the past few years so I’ve given it a miss.
It’s become something of a victim of its own success with the field being so big that on many of the cobbled climbs you are reduced to a snail’s pace and often forced off the bike and on foot as the road becomes too congested to ride.
Roubaix, on the other hand, has a fraction of the participants which makes for a safer, clearer run with fewer obstructions over the cobbles. The only downside of this is you can end up isolated on some of the road sections, where a larger field would provide more groups to latch onto for a welcome draft in between cobbled sections.