Thank you for the clarification.
retrolefty:
Voltage dividers should work fine. Of course you only require voltage dividers for the arduino digital output pins driving the RF module. The 3.3vdc logic signal outputs from the RF module wired to the arduino input pins must be wired directly as a 3.3vdc logic high is high enough to be read as a high logic level in a 5vdc arduino board.
I'm not sure I entirely understand you so I'll try to paraphrase. The 3v3 out of the RF module should be wired directly to the arduino's 5v input. I read the arduino could be driven with 3v3 inputs. This is what you're saying? Perhaps this is why many recommend the logic level converter as 3.3v doesn't technically meet the 5v TTL high requirements and the converter is sure to the right thing for a small price?
Thanks,