I have had an interesting experience, In the pre-round matches of men's doubles, we played each match as a single game to 21 points with changing side at 11. There were many chances you could get back from behind. No rush, no pressure to fight for a good start. Things couldn't be more interesting then, the tournament organiser decided to try out the 5 x 7 score system at the last minute before the final. Surprised? Try 'stunned'.

Look at the scores over 5 games: 7-1, 1-7, 3-7, 7-1 and 1-7. We lost, but that was beside the point. Both sides played such aggressive attacking games. The game was over so quickly, absolutely no come back once you were behind. More pressure for a good start, but then you pay the price of more silly mistakes under pressure.

Have your guys had any experience of 5 x 7 in a tournament?

yep, same happened to me and my partner during a local tournament here in IL. i have a bad habit of not warming up sufficiently before a match, and with the added pressure to play well immediately... (and i stink at this game too) we drowned our sorrows in a sushi bar.
oh well, maybe i'll get used to the 5x7 format someday.

I have not experienced this 5 x 7 (hope I won't ever have to). But I have been hearing about it. I was told that this will be the new format for badminton.. for a more "competitive" game.

Tell me, where can I get information on the "new" rules of badminton?

http://www.intbadfed.org/laws.html