Aware, I am not one to flame so please take no offense. I think you misunderstand the models. The c8 is the original Redfly. It has the 8 inch screen and the full battery life (8hrs+). It was D/C at the onset of the c7 and c8n.
The c7 has smaller screen and is quoted at LESS battery life (5-6hrs) and slightly lower weight. The c8n has the same battery and screen as the original c8 but has an added media port. If you are running the "old one", then you are running the c8. It cost 200 when it finally bottomed out price-wise "on sale". The new c7 is the lower price point(179-199). The c8n runs 299.
I recommend (unless video is a must and you have a separate player or a winmo phone with video out) that the c8 is still the best buy if you can locate one (ebay). If not, the extra battery life, screen size, and media port are well worth the extra 100-120 if you can swing it. That is this lowly geek's humble opinion.