Airave

Since the Airave is routing your call over the internet it is probably internet issues (connection speed, latency, traffic, etc.) The 5 bars just means your phone and the Airave have a good connection, it doesn't say anything about how good the Airave's connection is to Sprint over the internet.

I have heard of the Pre / Airave problem.  Usually the fix is pretty easy.  Press and hold the orange + sym keys and press the R key.  This will reboot the phone.  It should attempt to acquire a signal after this.  When it comes back up, dial *99.  If it worked, it should tell you that you're within airave coverage.  Although, I have had instances where the Pre wouldn't talk to the airave at all until the device was taken outside the airave's range and connected to a sprint tower.  Then, after the phone is brought back in range, it's fine.

Quality can depend on several factors.  Latency, Bandwith, Server Issues, Routing Issues ( a problem with a router between you and the server).  A good check on this can be to do a VOIP test.  http://www.voipreview.org/voipspeedtester.aspx .  Your jitter and packet loss should be at a minimum (in the green).

For any local issues with traffic (ie you have a teenager that's constantly playing WOW or downloading music), you can configure some routers to use QoS.  This is a way of giving network priority to a certain ip / mac address or a certain type of service on the router.  This will ensure that airave phone calls have priority.  If you're not sure if your router has this or how to set it up, just post your Make/Model of your router and I'd be glad to help you configure it.

any new or updated solutions to these chopy calls

First you need to give info about that router do you have