POE is bad for several reasons:

• It's huge and requires too many additional modules.
• It doesn't work on perl-5.004.
• It's rather slow. Ours transfers static pages 2 times faster.
• It doesn't have framework for handling several http requests to dynamic content simultaneously (entire slave/master framework would have to be written to support it).

In fact, implementing functionality we would need from POE (effectively - nice wrapper for select(2) with callbacks) is about 6% of all code size of SPWS.