Thanks to everyone for the replies...I really appreciate the help. I've had quite a hard time finding bend curve information for my mast which makes the situation even more uncertain for a beginner like myself. Not sure if there's any way to get a definitive answer (maybe contacting the manufacturer or posting a photo somewhere)? The mast was also used and much of the label was unfortunately worn off which makes it tricky to track down more information (plus I'm still not overly familiar with all the good windsurfing resources available out there).
I do tend to agree that the neilpryde sails seem overpriced but I really liked the idea of being able to fit a relatively big, powerful sail on a small mast and maintain a small yet versatile sail quiver. I also don't really forsee myself buying more big sails (8.5m or more) anytime soon. I usually wait for the wind to pick up quite a bit before going out. For the mostpart I've been quite happy with the 6.5 retro, but some days it's just not quite enough and I want something that can still push a little more on the moderately windy days.
I also like the idea of trying something different (brand, cams, etc.) to become more familiar with the options that are out there and how the differences change feel. I'll look into the other models everyone has mentioned.
Any more suggestions or ideas would be great! Anyone think it might help if I posted a photo of my mast?