Database overall quality and # of commented games
MEGA,GEGA why should I care ?

Quality means relevant games, correct game scores, homogeneous spelling of names, no duplicates, things like that
I have chessbase 11 with mega database. Its actually great and good to use for research in a position that you wonder if you should take or whatever you thought about doing.A lot of USCF 2200+ at my club swear by it for research on gm games. You get about 66,000 annotated games as well and updates weekly for the latest chess games in major tournaments.

I have chessbase 11 with mega database. Its actually great and good to use for research in a position that you wonder if you should take or whatever you thought about doing.A lot of USCF 2200+ at my club swear by it for research on gm games. You get about 66,000 annotated games as well and updates weekly for the latest chess games in major tournaments.
How do the updates work is it like opening chessbase again to see more games added or is it a pop up ?
I click update games button. The first year is free after that you need to upgrade but it will be a lot cheaper than at first paying.

are the updated games only of master games and are the games from diffrent sorces on the web or what ?
Whats the diffrence between Megabase and Gegabase for chessbase whats the diffrence between megabase and anyother chess database for that matter other than just the # of games one has.