We had a nice time on our 60 minute elephant trek. We wish that we had more interaction with the elephant...not just hopping on, riding, and getting off. We also thought the trail was dirty and pretty fake/engineered.
If you want to ride an elephant, which we did (despite what kind of conditions we might have encountered), the experience provided here is..ok. While you might consider alternatives, you're not going to find some perfect elephant harmony sanctuary there. You'll need to go to Chiang Mai for that...where the rescue elephants from trekking. Whether you're an animal rights activist or not, there's nothing very caring about "elephant trekking"...whether it's in Phuket, Samui, or elsewhere in a tourist-heavy location in Thailand.
We did the 60 minute elephant trek, which involved a quick roundabout a pretty basic trail. A third of the time was consumed by waiting for other elephant traffic on the trail to clear. We got some nice photos for the scrapbook, but there was little interaction with the elephant...which was kind of the point of going. Some customers got to play mahout and "drive" but that wasn't offered to us. The waterfall is pretty, again providing a great photograph, but there's trash everywhere and the entire experience expires in about 12 minutes tops.
I wasn't overly saddened by the conditions like many other reviewers...but that's indexed to other experiences and the fact that we sought out an excursion that, inherently, uses animals in a way that wasn't intended by nature. If that's not ok with you, then DON'T GO ELEPHANT TREKKING.