Back in an old job, we were running some pretty beefy Sun boxes (multi-processor E450s) that were pretty easy to tank under decent load (30k to 45k simultaneous connections). We later replaced the thing with a reasonably sized Nokia appliance (apologies - memory fades on the model/size/etc). Simply put, however, it blew the doors off the Sun box... literally no real comparison in terms of speed (same management box, etc)