Easy redemption of tickets but lines can be too long during weekends and peak hours. I suggest klook would include a fastlane in their voucher next time. Or a seperate line for voucher redemption.
Its a different experience but be ready to queue for quite a time depending on what time you go. We did visit st around 11am and queue for 30mins but when we did return at around 4pm the line going up was 4x-5x more already.
Great activity and good price. Queues we encountered in both directions however people we cutting in front of us and it seem a tour guide was encouraging this behaviour. More staff are needed to ensure that everyone joins the back of the que especially during peak periods.