There used to be a lot more suspicious NIN LB's, but it's definitely fallen off (alongside the declining NIN population). If there are still cheaters, it seems like they've limited themselves at most to auto-Purify/Guard. Wintrading and sandbagging I think are still around for sure, but obviously it's very difficult to prove without DM receipts or third party tools. Let's just say that a lot of T30 players each season have no business being there, given the way they play.