Having used the excellent free service for generating sitemaps (xml-sitemaps.com) I decided to but their full product today for just $20.
I am used to installing scripts but their documentation looked pretty good even if you’re not so experienced.
The bought version has several advantages over the free one notably no restriction on sitemap size and the ability to have your sitemaps updated automatically. It even has the facility to ping Google when your sitemap is updated, though if you genuinely do update your site frequently then I would not use this option – I think it’s always better to let Google decide when to crawl.
The license gives me unlimited use on my own personal sites too so all in all I’m very pleased and give this a thumbs up.
By the way – as with any script, do follow the security steps. Failure to do so could leave a security hole for your site.