I have read in different posts that the NN3 is really for smaller DSLRs and the NN5 should be used for the larger models, like my D300. However, I also saw a table that specifies that the NN3 is fine for the the D300 with a smaller lens like the Nikon 10.5 mm fisheye.

I am making an assumption that the heavier NN5 is stronger than the NN3. Given that I am reading different information in the posts that points in two different directions, with the setup proposed, which model should I buy--the NN3 or the NN5? Will both units work equally well? If so, I would prefer the NN3, because of its more compact size.

Also, if most of my work will be doing landscape panoramas, because of the distance involved, is it better to choose a different lens, such as the Sigma 10-17 and work at the 17mm end of the range? If so, under this setup, is the NN5 preferred?

I appreciate the advice.