Thanks RJP and everyone else who responded.
No it is not too late to return the wing, I got it from LeisurePro and they have a good returns policy.
My only issue is that if I was to go with the best single wings (according to consensus on this and other boards) - Oxycheq or DSS, I will pay an additional USD 180 (or thereabouts) for a new wing plus STA plus shipping (USD 80 to Australia).
Am I prepared to pay an extra $180 now, having only 13 dives under my belt? Don't think so. I don't think that with my current level of experience I will notice a huge difference between the super taco you guys describe with the rec wing and streamlined Oxy/DSS wings. I don't know, I could be wrong here?
I'm thinking I will dive the rec wing for now and then aim to get an Oxy or DSS wing when I get my regs - that way I won't waste the postage cost on just getting a replacement wing.
Money isn't an issue for me, but wasting it is. I am regretting making the wrong decision with the rec wing, but it will be a valuable lesson for me when picking gear!