The number of talkgroups you're scanning is irrelevant, because scanners don't check each individual talkgroup for activity, they check the control channels for talkpath requests and grants. It's the number of different sites, and therefore the number of different control channels, that impacts scanning speed.
The more systems you group together (Simulcasts A, B, and G, for example) the longer it will take to check all of the active control channels.
Which RWC sites you need to program in will depend on exactly which agency or agencies you want to monitor.
Looking at the link above, I see some of the information is outdated or just plain incorrect, and should be updated.
As for the LSM issues that plague the monitoring of the simulcast sites, Uniden's soon to be released SDS-100 scanner should alleviate those problems. Whistler has also announced two new scanners that should also better handle LSM issues, which are supposed to be released sometime between October and December of this year. Hopefully by this time next year, we will have at least 3 scanners capable of actually monitoring the simulcast sites.
Who do you want to listen to?
John
Peoria