Stata's strength is that you get a comprehensive stats package, including
survey facilities, in one powerful, reasonably-priced, sanely-licensed
package written by a highly responsive, user-oriented company. It is a
general purpose package, not a single purpose, dedicated survey package.
Stata's survey facilities will get you through almost any survey analyses,
but it would be somewhat unreasonable to expect Stata to do everything that
the best single purpose survey packages can do. If you want a comparison of
everything Stata can do versus everything each of the single-purpose survey
packages can do, the respective lists are long, so you'll have to check out
each website individually (try Westat and SUDAAN). Stata's capabilities are
listed here: http://www.stata.com/info/capabilities/svy/
I write to note that if your need is for complex survey methods, that
official Stata does not include replication-based methods (which SUDAAN and
Westvar do). However, my -svr- package adds BRR and Jackknife capabilities.
