The views are definitely worth it, as you will climb a flight of stairs, approx 350m upwards before you reach the falls visitors with health conditions need to be prepared). You can see the Langkawi cable cars from the top, so that's a nice trip to go on after riding the cable cars.
Water is cool and refreshing, but beware! Rocks are very slippery with moss and pools are deep. I didn't went for a swim, but opted to saok my feet instead - very refreshing after the long climb to reach the falls.
Now, the rubbish. There are a lot of signs in Malay, asking visitors to PLEASE take down their trash, but could be because most visitors can't read, the rubbish were thrown in the toilets instead! Really bad behaviour from visitors! But that said, maybe the management can put signs in different languages as well, so visitors can be reminded to take down their rubbish after visiting the falls.
If you do need the toilets, go to the ones near the entrance before climbing the falls. Those are much, much cleaner.