Failover In Themes


I´ll just started using themes in Yii since my users requested different look-n-feel for a up and running site. So far I love the theme functionality but get a little bit worried about best practice.

My main concern is the failover, when a view-file in the theme is not found the standard file in /protected/views/something/ is used instead. I use this quite a lot since the only thing that changes between my themes so far is the layout-files, css, images and some js. This means that almost all view-files are looked for in the theme directory but not found, then loaded from the standard view path.

Is this an ok practice? Is there a "big" time or performance penalty involved? The site not not under extreme load but still, i want it to run smoothly and not flood-fill any error-logs. So is the theme module "ok" to use as described above or can/should I improve it?

Hope you understand my question. Thanks!

I would like to here an answer from the yii community on this one as well. Does anyone have any input on this?