2230.md

The dynamic keyword has been introduced for interop with languages where properties and methods can appear and disappear at runtime. Using it can introduce a serious performance bottleneck, because various compile-time checks (such as overload resolution) need to happen at runtime, again and again on each invocation. You'll get better performance using cached reflection lookups, Activator.CreateInstance() or pre-compiled expressions (see here for examples and benchmark results).

While using dynamic may improve code readability, try to avoid it in library code (especially in hot code paths). However, keep things in perspective: we're talking microseconds here, so perhaps you'll gain more by optimizing your SQL statements first.