completely agree (and I am a Sarries fan who has been to Edinburgh at Murrayfield).
The Olympic stadium needs to be used regularly, and it needs to remain an athletics stadium. As I understand it, that is what will happen with West Ham winning the race out of the self-interested little nancyball shits who've also bid (Spurs and Orient). The athletics track will remain, and the stadium will be used regularly, by an East London team, so I'm satisfied.
There's not too much point in Saracens using it. Rugby Union is popular in West and South London, not so much North and East. Saracens are planning a move to Barnet Copthall, which is back to where the club is originally from and looks like a great option considering the attendances we usually get. Heineken Cup, and other games, can be moved to Wembley, and we've already proved this can be done successfully.
Wasps, Quins and Irish are in a different position. Quins have a cracking ground, and Twickenham is natural for them to use for bigger games. Irish play in front of the Madejski with loads of empty seats, but it can fit a lot more people in it for bigger games. Wasps really ought to be thinking about a move back to London imo; High Wycombe is not a good place to be. But they should move back to West London, I thought Loftus Road was great for them. Either that or Craven Cottage could, potentially, work. I would suggest Stamford Bridge when Chelsea eventually have to move out, but the price will be astronomical.