I've had a suction cleaner (Mamba) for the last year but it never does its job very well. I'll leave it in overnight but then it'll get caught on our ladder. It also tends to favor one side of the pool over the other so one side is very clean. So, I've about decided to buy a robot. These appear to have the best reviews at the best price. Is the extra $100 for the S2-50 worth it? Are there any other options that may help with my issues that aren't $3-400?