That's the greatest difference, though there are others. John Nunn's Secrets of Practical Chess (Revised version) goes into this in more detail.
TWIC games and chessbase megabase

That's the greatest difference, though there are others. John Nunn's Secrets of Practical Chess (Revised version) goes into this in more detail.
Can you give us a bullet point or two from Nunn?

ziggurat> What is the difference beetween chessbase megadatabase (or some similar product) and downloading the games from TWIC and build yourself the base?
- Each TWIC update takes about 15 seconds to add to your database. It will probably take you more than 3 hours to add all of them correctly.
- Your database will contain about a million games.
- Your database will only contain high-level games.
- Your database will only span from 1999 to 2009.
On the plus side, you don't have to pay the $40 USD it costs for the Big Database, which comes with 4 million games of all levels from 1475 to the present.

The Megabase isn't an apples to apples comparison. It's basically the Big Database with 60,000 games annotated for an extra $100. If you're in the market for annotated games then TWIC would never fit the bill since it's unannotated.

The best way to do it is buy a copy of Chessbase as it comes with I think the big 2004 database. Then download the TWIC yearbooks up to 2005 - 2008. Then you have a current up to date reference database. That's how I did it.

lochness88 - Agreed, for me, there's no need to re-buy the Big Database every year.
What is the difference beetween chessbase megadatabase (or some similar product) and downloading the games from TWIC and build yourself the base?
I know that the chessbase databases has some annotated games, that's the only difference?