This is what I'm riding these days:
It's got both aluminum and carbon fiber portions of the frame.
IMG_20170305_115734_604 by
Nate, on Flickr
The seat stays on it are carbon fiber. I also have carbon bars, which make me really happy in wintertime, as they ARE warmer.
My wife's mtb has more carbon on it than any other material, I think.
20170419_154451 by
Nate, on Flickr
It really changed my mind about carbon on mtb's. She's wrecked it in the rocks, and the clear coat is scratched but the bike is fine. The frame is 7yrs old, too. Nice thing about carbon is how repairable it is. Aside from the cost, I wouldn't hesitate to buy another carbon mtb. We saved on cost for my wife's mtb by buying it used from a racer who used it a couple seasons. Got it for basically the value of the components and really checked it over once it arrived. Wife is looking at buying another carbon mtb with more suspension travel this summer.
My road bike is steel. Grades of steel vary a lot. Surly tends to be much more basic in its construction. Stiffer for sure. Less tubing wall thickness manipulation. Etc. Salsa steel bikes are a little nicer. Better steel alloy, a little lighter, a little more compliant. Salsa doesn't do as many steel bikes as they used to, though. They have more alu and more carbon models. Far fewer Ti models, too.
20170218_162144 by
Nate, on Flickr
I'm personally thinking hard about the new Santa Cruz Chameleon. I'm liking a lot about that bike, and reviews I'm reading are saying it rides SUPER nice, especially considering it's aluminum. They're hard to get, though, and I don't think I'll even get to test ride one for a few more weeks. I'm thinking I'll probably buy it in 27.5 plus configuration and maybe add a 29er wheelset to it later.