Assign each power besides your current a number 2-12. Use a virtual dice roll program or a pair of dice you have around the house. What ever you land on go with that power. Just don't do a do over if it lands on something you heard bad things about.
currently celestial right now and i am having a ball right now... so if you want to remain a heal power go there if not ... how about gadgets i've been eager to try it out since intimidate is suppose to have a new effect one paralytic dart and EMP ... which can make constructing a new loadouts and rotation more exciting than ever
If you want to try something new, wait and try munitions. If not just pick up the one you feel is the best for you. I cant tell you any power because you didnt specify any role
I say switch to a new power you haven't been before. Keeps the game fresh. I'm really excited about munitions. I'm having a internal debate on switching. Instead of switching my main's power from ice I will do it on a alternate. On a sidenote by playing different roles you understand raids much better and makes you a better player overall.
Head to test server and try things out. If not on PC... *shrug* there's no helping you. This is your decision, not ours.