The are some important changes in the map (e.g. the new segment of the S69 Bielsko-Biała - Żywiec opened, the bypass of Augustów - S8/S61 opened) which have not been included in the last two updates. Does anybody know why?
On the other hand some minor OSM changes (such as new gas stations) were included in the update only a few weeks after they were made. It seems that there's no general rule.
What is "a few weeks"? And yes, there is no fixed schedule, that you can be sure that you have your update on the same given day of a month.
If changes in OSM data just miss the the date, when Mapfactor downloads the data file and processes it country by country the following days, it will take four more weeks until the next download. If the changes are made to OSM data just before the download, those data can be processed by Mapfactor and released earlier. You may find the process described somewhere in this forum. Futher delay may be caused by data errors on the processing process or given in OSM (search the forum for examples).
Until now they have everything worked out sometimes with some delay.
Anyhow map updates are much more frequently than those of any commercial software I know and they are free!