We got in touch via email and confirmed just 2 days prior. Brochures we picked up in Seminyak had similar tours advertised for 2,100,000 IDR per person. We paid the advertised website price of 900,000 IDR per person for a group of 3. The whole tour was just the 3 of us an our guide. My cousin also booked just a rafting tour and got a significant discount for a larger group. Also, when you're arriving, you can opt to pay an additional amount (I can't remember now) for a photographer to go along the route and take photos of your group at various photo points. I'd say it's worth the additional cost because you can't capture the rafting experience from within the raft.
We chose this water rafting and would recommend it to first timer adults. It wasn't challenging and felt safe with just enough thrill and splendid views along the river. It's a slightly longer river which also added to the enjoyment. We didn't have watershoes so we just wore our sneakers which works fine. I felt safe but there is potential for injury as we saw another boat of 4 had flipped, I would assume it was human error and the guests had panicked and shifted weight suddenly. It was a different tour group, but I honestly think they're all about the same. It's the same river.
An exciting moment was going under a waterfall where we also had a pitstop. There's also a bit of a drop at one bit for a bit of thrill, but don't get too hyped about it, it's just like going fast down a slide, it was over before I knew it. The actual fun came from paddling and splashing one another down the route. Even splashing and "racing" other rafts. But really, there's no need to paddle if you're not comfortable as it is pretty much guide-steered and just follows along the river.
Showers and towels were provided followed by lunch.
The ATV ride was back in Ubud. We had concerns having read articles about quad bike deaths from rolling, but this was concern was not a real one to have because the more adventurous parts were through tracks where the walls would go up on either side (making it impossible to flip). The path is pretty well worn that you know where to go and can't really get lost. Just go at your own pace, there's no real danger here. It DOES feel like a rollercoaster with thrills and parts I was howling at. But if you're doing it as a way to see ricefields/villages then I'd recommend doing a cycling tour. The ATV was more for the excitement of riding an ATV. Muddy waters and sculpted hills and turns add to the excitement.
Definitely say you should do the water rafting. ATV would be up to the individual though as my friends thought it was great, but I'd give it a miss in the future.