I have a giant rapid 3 that is now becoming my commuter bike. It's not a cyclocross bike, it's a flat bar road bike, but quite frankly it's geometry is very similar to a touring or cx bike. I already converted it to a drop bar bike so my gf could have the flatbar shifters on her bike since she didn't like the drops. I just put 700x35 tires on it with zero issues. It has regular road bike long reach brake calipers and the big tires fit easily, I could probably go as large as 40s if I really wanted to but I don't see the need.

I live in NYC and there is a bike lane on 1st ave that I take on my short commute to work that is just one big pothole with a seam running down the middle of it because the road is concrete slab, not asphalt. I was tired of worrying about my 25c tires getting caught in that crack. These new 35c tires are great, much softer ride for me and I can hit a lot of the smaller potholes with no issues I also weigh 235 so the softer ride is nice. My rapid 3 was 550 bucks new and has mounts for fenders/rack on both front and rear. Ijust put the bigger tires on today and added the rack and looking forward to commuting on this as it's a pretty quick bike.