My experience is that RepeaterBook has a more complete and up-to-date list of amateur radio repeaters than RadioReference.
Note that RepeaterBook is not all that accurate, either. In one Indiana county listing on RepeaterBook, 73% of the listings are incorrect. Half of the repeaters listed for this particular county are off the air.
Not a knock on RR at all ... remember that the database is crowd-sourced, so what's in the database is only as good as what has been submitted by local hams (or unlicensed listeners).
RepeaterBook is also crowd-sourced. Publishing crowd-sourced data is no guarantee of accurate data.
Local ham radio clubs probably have repeater lists that are better than what either site has.
You would like to think that local ham radio clubs have a pretty good handle on local repeaters. However, some local ham club websites are hopelessly out of date, so I take their data with a grain of salt, too.
Illinois and up to nine other states' repeater coordinating councils do NOT contribute to Repeater Book, RFinder, or the ARRL "Official" Repeater listings.
The Indiana Repeater Council does not provide data to the ARRL, RFinder, or RepeaterBook, either. We have our own online repeater listing that is as accurate as the data we have in our database. But, as you know, even coordinators' databases are only as accurate as the data provided by the repeater trustees.
You will most likely find the need to use multiple sources when compiling repeater lists...Unfortunately, there is no single authorative source for accurate amateur radio repeater info.
I agree. There is no one, single accurate source for amateur radio repeater data.
This is one of my major issues with ARRL: the organization has the resources to compile and maintain a reasonably accurate national repeater database, yet fails to do so.
The organization
had the resources to do this and was doing it as well as could be expected given their annual publishing schedule for the ARRL Repeater Directory. However, a now-retired CEO hired an outside firm, RFinder, to compile the data which is used in the ARRL Repeater Directory. Unfortunately, RFinder wasn't entirely forthcoming with the repeater coordinating councils about how their data would be used and who could edit it. Also, the ARRL had a financial relationship with the coordinators (who were compensated for their efforts with a a small fee paid by the ARRL per repeater listing) that RFinder did not wish to continue. It became a matter of principle since RFinder was going to make money from the repeater data, but the coordinators who were to provide the data wouldn't be compensated. Many coordinators, as Will mentioned above, elected to not participate with RFinder.
I had numerous conversations with my ARRL division director about this situation and he agreed that the RFinder deal needed to be addressed. But, then, the directors got tied up with hiring and firing key staff people, a failing IT system, and a pandemic. Then, my director resigned. I don't know how my new director feels about it.
In the end, the annual publishing of the ARRL Repeater Directory is an anachronism that really needs to go away. There is no way that a directory published annually can keep up with the changes. The ARRL, in my opinion, should work with the coordinators to develop an online repeater directory that can be fed from the coordinators' databases. This should have been done
in house several years ago rather than hiring a less-than-altruistic third party to do it.