How hard it is to land a fish depends on how big the fish is. I fish with a line that is 13' long, including tippet (1' longer than the rod). Any longer than that and you will not be able to net a nice fish, because the rod bends quite a lot. With a fish up to 8 or 9", just raise the rod tip and in he comes. A 12 or 13" fish is going to race around and jump a bit (even the browns, it seems) but they'll succumb pretty easily. A 16 or 17" fish will make you wonder if you'll be able to land it, although unless it's in current you should be able to. Much over that size and my money would be on the fish. My best is 17 1/2". I've hooked two fish I couldn't land, but both were before I could get a real tenkara rod. The first was because my line was too long, I couldn't net it and it broke my tippet when I grabbed the line. That's how I learned to limit line length to rod length plus 1'. The second was once when I was fishing with 4x and a graphite panfish pole that looked just like a tenkara rod but was a lot cheaper. Turns out it was a lot weaker too and it broke when the biggest trout of my life took off and I couldn't stop it. From then on I've only fished with 6x. A tenkara rod will protect a light tippet very well. Conversely, a light tippet will protect a tenkara rod. There is a post on the Tenkara USA forum from a guy who hooked a carp and ended up breaking a 3x 8# test tippet trying to beach the carp with his new Yamame rod. If you try to break 8# test line in a steady pull, that will give you an idea of the strength of the rod. I'm actually a little surprised.
I have two rods from Tenkara USA, a Yamame and an Ebisu, the Ebisu is the 5:5 model, which is a much slower rod than the Yamame. Both of them are much nicer than any of the crappie or panfish rods I used before I could get a tenkara rod. I was given an older tenkara rod a little over a year ago by a Japanese angler. As far as I can tell, the Tenkara USA rods are at least as good (and the cork on the Yamame is considerably better). Keep in mind, though, (A) I've only seen one other tenkara rod, and (B) they're the only game - not only in town but in the whole country. If you want to buy a tenkara rod, you buy theirs or import one yourself from Japan. I'm happy with my Tenkara USA rods, and this whole thing is about simplicity, right?
I haven't fished RMNP for decades, but as I recall the streams are really quite small and either brushy or tree lined. You might be happier with his 11' Iwana (I don't have an Iwana so I can't speak from experience on this one, but it is his "small stream" rod and his descriptions of the rods I do have are right on the money). Also, one of the panfish poles I had (and the one I broke, actually) was 10', and I always thought it was just a little bit short to do what I wanted to do. I think an 11' rod would be a very good compromise - at least it's the one I would want for RMNP, or rather, for my memories of RMNP).
edited to add: I wish you hadn't mentioned RMNP. I'm going out to Colorado this summer to visit my mother, and you've just complicated my trip. I wasn't planning on fishing, but now that you mention it...