I disagree and have written a detailed post on Serr.biz. http://www.serr.biz/ask-a-question/joom ... ation.html
The short of it is this.
I have conducted hundreds of SEO audits over the years and constantly dynamic sites (like Joomla) with SEF out rank sites without SEF.
To that point, let’s do a search now and see. Search "Joomla SEF" in Google.
This is what I see (I'm in the USA. Results may vary according to your location.)
--Google Results 10/02/07 --
- 44k - Cached - Similar pages
- 48k - Cached - Similar pages
- 15k - Cached - Similar pages
- 38k - Cached - Similar pages
5)www.joomlatwork.com/products/free_products_for_joomla/sef_patch_joomla.html[/b] - 24k - Cached - Similar pages
- 41k - Cached - Similar pages
- 63k - Cached - Similar pages forum.joomla.org/index.php?topic=71463.0;wap2
- 4k - Cached - Similar pages
[ More results from forum.joomla.org ]
- 17k - Cached - Similar pages
- 27k - Cached - Similar pages
-- End Results --
If you look at the results, you will see 8 of 10 are SEF, even the number one ranked page, Joomla extensions directory, uses SEF.
5 0f 5 have the keyword SEF in the URL.
Joomla forums is the ONLY site not using SEF.
Also, most of NON joomla pages with the full URL and .html extension or ranked better than SEFS ending in a /
Regarding Google Site Maps, I'm torn, personally, about their effectiveness. I've used them in the past, and am building an addon for SerrBizSEF, but have experience a lack of "Google bot" activity because the site map is not updated enough. My recommendation is to use Google Site Maps if you can update it regularly. If your content is not changing that much, you might be better served just "verifying" you site with Google Webmaster Tools and letting Google find you often through RLP.