NO!! Don't upgrade.  My voice to text on Jelly Bean only works at home with a 5 bar signal & wifi.  It has worked in a Tmobile store, nowhere else, even with strong signal. If I wait long enough for the voice prompt (usually 1 min+), get message "can't connect to google".  Also, sucks down battery life by a good 30%.  I'm having T-Mobile send me a warranty replacement because I can't go back to Ice cream Sandwich (4.0), even if I do a factory reboot.  I'm not familiar with forums (1st time), but I make the effort because this new upgrade shows how incompetent HTC is (not sure if T-mobile shares blame here).