I'm not aware of any specific Viper 4+ issues in latest software.  Many techs generally wouldn't recommend latest software updates for many things if you don't have a specific need.  So I guess I'd question:
*Did the tech's mention any specific issues?
*How far behind is the Viper 4 with the current software version?
*What new features are you looking for by performing an update?  Would you also update the various node's on the system?
*What is the Viper 4 currently controlling?  Steering via SmarTrax?  Likely product control.  How about boom height control?

What did you get for a sprayer?