A quick questionnaire about xwiki at your orgainization

Dear Community, My organization(a division in a US Federal Government agency) is going to select a wiki engine for a trans-organization collaboration effort. The current candidates are Confluence, XWiki, MediaWiki and Microsoft Sharepoint Wiki. I tried to promote XWIKI but have only used it in a very small scale environment (< 5 users). If you have used it in a production scale and can provide me some feedbacks based on the following questionnaire, it will be a great help for me to show to my manager. Thank you in advance! -Jimmy ================================================= Capability * Number of wiki users at your organization * Number of maximum concurrent users Wiki Engine reliability (on a scale of 1 to 5, 5 is best and 1 is worst) Usability * Wiki Engine usability (on a scale of 1 to 5, 5 is best and 1 is worst) * Training / learning curve (on a scale of 1 to 5, 5 is easiest and 1 is most difficult) Cost * Hardware requirements * Cost (license fee, hosting fee etc) Support * Data backup and recovery (i.e. do you have daily back up procedures in place and is it difficult to backup and recover the data if there is a disaster?) (can you restore just a page or space instead of the whole wiki if a page/space is messed up?) * How difficult is the administration? (i.e. roughly how many hours the administrator need to spend on the wiki maintenance?) * How is the quality of support of this wiki engine (from the commercial vendor or the community. i.e. can you get timely answers for your questions?) (on a scale of 1 to 5, 5 is best and 1 is worst)