LSM trees are good for frequent updates on recent data. Frequent updates of old data are much worse on LSM trees since they trigger merges on the oldest (and typically largest) levels of the tree.

Some storage engines allow for in-place updates of records if the fields are fixed-length or if the updated variable-length value fits in the existing space. I've used some of those (e.g., MS SQL Server) to good effect in high-update scenarios.