re: For some entries it is taking what I consider to an excessive amount of time to load the preview – is this normal?
SiteShot uses a WordPress.org service to provide the screenshots of websites. When you view your directory, SiteShot send a request to that service. That request enters a processing queue. If that processing queue is busy it can take a little time to get a thumbnail. In my experience though, usually the thumbnail is available within a few seconds and will appear in the next page load. Now, if a site that is being screenshotted is slow to respond the WordPress service will move on and come back to it as to not hold up the queue. At least that is my best guess based on experience because I do not have any real insight on how they manage that processing queue.
re: If an entry has a logo image – will this override the SiteShot preview?
No, but, it is possible to use a SiteShot as a backup if there is not image/logo. You would use the
image_fallback='siteshot' shortcode option in cMap.
re: Can you choose for which entries you want a SiteShot image or not?
Sorry, no. It all or none.
re: Do the Site Shot previews have an effect of load time for a page?
I’m sure it does. It could be positive, negative or even no difference. It really depends on a whole host of factors which will be different for each site. The best way for you to tell is to load the page 10 times clearing the browser cache after each time and average out the page load time. Do it twice once with SiteShot loaded and once without it.
Hope this thoroughly answers your questions.