I am at L2 now and it took me 6 tries in L1 to finally passed it. Agreed that the long waiting time to book the next lesson is a huge turn off. Whatever instructions and procedures for the riding could have been rusted by then. For me, the most discouraging part was the instructors. Some instructors are nice (Nizal, as you mentioned) while some are...#nastydefensivefullofegogansterlikebehaviour. Before every lesson, I got nervous and demoralised just by thinking which type of instructor will I get this time. If I were the management of SSDC, it's about time to implement annual appraisal and performance grading. While I may not have met all of the instructors there, in terms of having a good attitude, so far I think Nizal and Alson were the ones worth mentioning.
I have not booked my next lesson yet, kinda dragging my feet now lol.