We love Sesame Place!
We had a season pass last year and went several times (probably 7 times) and we just went monday. It's an hour and half ride for us or else we would go more. If you have young children it's one of the best parks.
We have gone so many times and have never found it to be dirty. We do both the water rides and the dry rides. Usually start off with the water rides and then change and do the dry rides at night when there aren't any lines. We always go on weekdays because i hate crowds and when we had a season pass we would go at night after 3 when crowds we less too. It's great for little ones because they can do practically every ride. Plus it's not too small and not too big so you aren't exhausted walking around it. There are character meet and greets, character meals, and shows as well.
My only issue with Sesame Place is the expense. If you don't have a coupon its about $48 per ticket for ages 2 and up. Plus $13 parking and $12 for a locker. A lunch for four is 2 kid meals and 2 meals for adults is about $50. We really enjoyed our lunch. We got a ham and turkey club sandwich and it wasn't cold cuts it was carved ham and carved turkey. Very yummy.