Re:Tikiwiki perfomance
I'm new in tikiwiki (just few weeks) but I come from others CMS experience: Postnuke, Envolution, MDPro and Typo3.
Tiki is really speed compare to postnuke and Envolution and also MDPro, don't consider the time that take the first time you charge a page, it is due to compiling templates for the pages requested and it is a good advantages for performance the second time you request same pages. Try it.
These Smarty template works very well.
You must consider the features you need from a CMS.
For istance:
Typo3: not easy to manage, very quick, excellent for customization and for site development, quite poor for extranet/intranet and community also.
Envo and MDpro: very good for community and customization (MDpro in particular), not so poor for extranet/intranet and poor for site development.
Tikiwiki in my opinion is great for extranet/intranet and communitty and, considering the template system it's also very customizable.
Summarizing: reconsider your idea on tiki performance, and for your soaring club compare MDpro (www.maxdev.com) and Tiki basing on features you need.
MDpro more smiling, Tiki more professional
good fly
luca