I just find custom windows perform so much faster for certain tasks than dialog lists, especially when loading up large text.
As mentioned in another thread, loadbuf to a custom window is instant, whereas to a dialog list can take minutes to half an hour depending on file size.
I know dll's exist that can let people do this, but it would be nice if mirc could do it without the need for downloading dll's.
Alternatively, improve dialog lists so they are comparable to the custom windows in terms of function speed.