I think both exception loggers are similar. Both tools can attach additional files to the exception reports:
From time to time there are threads in the Delphi newsgroups which ask for a comparison of both tools and normally both tools are recommended. I think it’s best to test their trial version.
There’s an example in the SmartInspect online help (press F1 in the Console) which explains how to use the memory protocol to create log files which could then be used as exception report attachment. It can be found under “Working with SmartInspect | Connections and Protocols | Memory Protocol | Delphi”.
And finally, yes, the backlog feature can also be used with the memory protocol. The backlog option is a protocol option which can be used with all built-in and also custom protocols.