I have been in contact with these magical load balancing appliances for many years now, every company that run a middleware setup and thats all of the ones i have worked for. be it Weblogic Websphere, or JBoss the common item is an F5 load balancer.
The training course is well worth it if you spend any time administering any of these environments as you really get the chance to go deep into the guts and the capabilities of these wizard like devices that are usually re-severed for the high priestesses of Comms Geekdom. Well we looked at the LTM or local traffic manager and its mirriad of pools, snats, profiles and virtual servers all of which serve to ensure that your web presence is available.
The GTM is the next level up in the food chain if your organization has multiple locations or even a disaster recovery site one of these in addition the LTM is advisable. The DNS functions are well worth it, the cool function we played around with was configuring the DNS Express this is like DNS resolution on steroids the bigip basically acts as a secondary authoritative DNS server and takes the load of the back-end server resulting in lighting fast resolutions.