I have been to several of these in past years, found them most worthwhile, and am tentatively planning to attend this year. The event is great for both formal learning (with CPE credit) in the sessions, and personal networking in the hallways and social events.
I checked the difference in hotel reservations between going through the ISSA.org site versus reserving directly with the Omni Mandalay. The ISSA group rate is definitely better.
For Community members not familiar with the variety of organizations in our field, you should know the tISSA is not a competitor to (ISC)2, but is, in fact, one of the professional groups that founded (ISC)2. ISSA does not have certifications, but chapters routinely help members prepare for the CISSP exam.
I heartily recommend joining ISSA and considering attending both local chapter and international meetings.