[intel352]

DSEFU essentially performs the same functionality as XC SEO.

DSEFU is a commercial non-free closed source mod for X-Cart, XC SEO is a completely free open source mod for X-Cart

they both redirect users from php URLs to HTML urls, replacing the static HTML catalog functionality of X-Cart.

when XC SEO it had a more complete feature-list than DSEFU, but since then, DSEFU has caught up, so both mods are very similar, only difference is Cost (DSEFU of course comes with support, since they charge you for the mod, which always is a good thing to have).

If you want an SEO mod that would be a "step up", I would have to recommend CDSEO (websitecm.com), as it allows you to fully customize your category and product urls.

Cheers

-Jon Langevin