I will say, we were hesitant to book this hike concerned about how rigorous it sounded in other reviews, but I am SO HAPPY we did!
This was our first time in Cinque Terre and my boyfriend and I both agreed that it really took the stress off of us to have tour guides leading us through each of the villages and letting us know when to be where. We enjoyed being able to have a little time in each village and, when we return, know where we want to spend further time in.
In regards to the hike, it was on the tougher side and it was quite hot the day we went as well. I also stupidly forgot my inhaler, so that made it extra difficult, but that's all on me. Even with a few stops to take in all the breathtaking views, it was absolutely doable. There was so much flexibility in the tour as well in terms of if you want to join the group for lunch or not, where you can wander around to, and you can even decide to skip the hike and take the train over to the next city if you aren't up for it. I highly, highly suggest hiking though! I still daydream about those views.
All in all, our tour guide, Alessandro, made everything super stress free and made sure we got through everything in a timely manner. Loved every minute of it!