I think its a combination. I'd its faulty, they replace the module. If not, it gets reworked to make sure its at Max strength. then the antennae attenuation is tweaked(not sure if this is done thru hardware means or a matter or reprogramming software). then they make sure both wifi & BT are on their latest firmware. I don't know too much other details other than they've been having alot of success reworking the units with some new method and adjusting the antennae attenuation. they even said one of the reworked units had slightly better wifi/BT reception than an infinity pad tested side by side. the infinity pad just doesn't have a plastic strip thrown up there and that's it. they adjusted the antennaes attenuation in it also. but surprised me when they said the reworked prime had better reception. So there still "MIGHT" be hope for the prime reception.
one question though : do you think that even they manage to find a 100% efficient solution, will they let everyone aware that a fix is possible. And if not, for example here in Belgium, I can't even file it for a RMA since they refuse to acknowledge that there is a problem with the wifi. It is only possible if the unit can't connect or wifi isn't functional at all (which was the case with the first prime i got but the retailer was cool enough to replace with my current unit with no fuss).
Honestly the signal strength was never much of a problem for my current unit, but the dl speeds were really low when away from the router. other than that (and of course the gps that I don't use and that i don't care - and just for the record, the dongle didn't help either) the unit is great and i didn't experience all of the different issues that i've read in the forums (one other strong reason why i don't want the RMA messes things up).
On top of that, i really fear that, with the upcoming launch of the infinity 700, the prime users will be completely forgotten...