I just canceled my subscription to EF which was really useful for identifying flights where I was highly likely to be upgraded to business for free.
The issue of brokers is strange to my mind - it used to be really easy to find award seats with partner airlines. Now more airlines are moving to dynamically priced awards and want you to book that seat with them for 120,000 miles rather than 50,000 with a partner. So there are fewer available to their partners at the standard rewards rates.
As such, you really need a lot of patience and extra time to find available seats (constantly manually searching for partner flights). Alternatively, you could use one of these companies that regularly checks other websites (which are displaying public information) and alerts you when something you are interested comes available.
It is kind of like if someone were to set up a search on interval alerting them to available exchanges at certain resorts for certain time periods. The TUG sightings forum is an example of something that could be shut down if the legal theory behind this is correct as it has a similar purpose (just not automated).
I paid a fee for EF, but some others like Cowtool were free. There is a huge discussion about this over in FlyerTalk if you’re interested.