OK
1. Don't know about other makes - I have a Sargent on mine which is great for me and made a big difference to the 4S seat, but the seat on my ST2 was comfy enough as it was..
2. Yes...lots more.
3. Loads - I go away for 10 days on the continent and need no more space than that of the panniers.
Andy
[Edited on 7-12-2004 by Rushjob]