Hills, hills, hills. The hardest thing for me to get used to after moving to CO a couple years ago was climbing for 5-10 miles straight and then descending for the next 5-10 miles. There are definitely flowy trails here, but most of my favorites are long descents preceded by seemingly longer climbs. Where are you planning to ride while you’re here? That could be a determining factor as well.
..Salida area, probably Monarch and cottonwood, maybe something else depending on where my buddy wants to go. I did those two last year and the first couple miles of Monarch was much harder than I anticipated after factoring in elevation.