I've toured in CR and found it only so-so for touring. It's an extremely mountainous country with some beautiful scenery and national parks. The paved roads were often in surprisingly bad condition. If you're near sea level, it's quite hot. The only flat road I saw is along the Pacific coast. South of Quepos, it wasn't paved when I was there, though it was in decent condition compared to some of the paved roads. There was decent riding near Arenal volcano. Some of that was unpaved. I also biked down to the Caribbean coast via Turrialba. It was a fairly enjoyable route. I think there's a short fairly flat road from Limon to the Panama border but it was pouring down rain incessantly on that coast and I never made it beyond Limon.
Nicaragua has had some serious political violence over the past year.