I would still try another airave/Airvana. It won't hurt you and Could help. They are on version 2.5 now, so you won't know until you try the new one. If you're willing to wait, then wait it out. With the new plans and the situations arising, why not leave to get better service and come back if it is the better option for you at that time?
If i was having issues with voice/text, i would leave. Most of the time though, my service is good enough and if data doesn't work, then I deal with it, but coming from nextel years ago, i'm fine with some of the 3g speeds i get.