I have two nice road bikes. One all carbon fiber, one all steel. So I can offer a comparison.

The carbon fiber bike is a 44cm 2007 Specialized Ruby. It's a nice bike. I've changed out some parts: handlebars are now Salsa Pocos, wheels are Mavic Open Pros. It used to have nice Ultegra quality wheels, but I thought the ride was a bit buzzy with them. The Open Pros really smoothed out the ride. I use 25mm tires. This bike is supposed to be a "plush" ride, and it does ride nice. But I think my steel bike rides a bit nicer.

My steel bike is a Gunnar Sport. It has a moderate quality steel fork from a Surly Pacer on it. The Gunnar is a high quality steel, OX Platinum ans 853 steel. The bike I have is a custom geometry bike. It wasn't custom for me. I got on ebay second hand. It's about a 41cm frame that takes 700c wheels. (Gunnar offers stock size frames and the smallest Sports have 650c wheels.) My Gunnar also has Mavic Open Pro wheels. This bike has a dreamy smooth ride. I've done climbs and descents (on bad pavement) on big passes and a few centuries on this bike. It's a couch.

I have not done such big rides on my Ruby. Not that I think it would not be nice. I just can't carry much on it. I have a rack on the Gunnar to take a few things on all day rides, so it usually made more sense to ride that bike.

I think my steel bike rides a bit better than my carbon bike. The carbon bike is a bit faster, but I'm not a fast rider.

Sometimes I do worry if the carbon bike will 'splode. Highly unlikely tho.

I did a big ride over Slumgullion Pass near Lake City, CO a few years ago. The descent was on rough pavement with mile after mile of lateral cracks. Kachunk Kachunk Kachunk Kachunk for a long long time. I was glad to be on my all steel bike. I had a 110 mile day that day. I recall at mile 98 feeling pretty darn good, shifting down and hammering a bit.

I think Jamis makes nice steel bikes. If I was starting from scratch and needed a steel bike I'd be looking a Jamis.