from what i've learned with webservers it depends on implementation: cipher-suites, keep-alive, session-ticket-reusage etc. this pic shows the perfomance for a webserver w/ different cipher-suites: https://8ack.de/static/bimages/ssl_perftest_r1.jpg
speaking of webservers, if you use the usual performance-tweaks you wouldnt see a big performance-drawback from userperspective (YMMV)
from what i've learned with webservers it depends on implementation: cipher-suites, keep-alive, session-ticket-reusage etc. this pic shows the perfomance for a webserver w/ different cipher-suites: https://8ack.de/static/bimages/ssl_perftest_r1.jpg
speaking of webservers, if you use the usual performance-tweaks you wouldnt see a big performance-drawback from userperspective (YMMV)