Not only is the Martial secondary set great - a bit broken to be honest - but LOOK LOOK:
/Devices' Cloaking Device is now Field Operative, which grants a large buff to recovery and regeneration while also still granting stealth; and Targeting Drone easily enables instant-cast snipe 100% of the time!
/Electric's Lightning Clap is now Force of Thunder, which grants a large buff to recovery and regeneration in addition to its amusing knockback effect!
/Energy's Conserve Power is now Energize, a fairly large self heal click that also still applies a large endurance cost discount!
/Fire's stupid 'taunt aura' now gives very significant selfhealing per second and buffs recovery!
Add to this the many changes to IO sets (they got really free with smash/lethal resist), new story content, and that you have no reason to farm merits or money to obtain the good stuff (IOs are free from the Beta points market) - oh you're not VIP? That's okay, get an invention license from the points market and see what you were missing out on with all that IO stuff!
ARE YOU DUMB? ARE YOU CRAZY? WHAT IS WRONG WITH YOU! GET ON BETA!
e: Instructions on installing the beta client can be found here:
http://paragonwiki.com/wiki/Beta_Server