Why not get it for a month on the Developer licence, to try it out? Or I believe there is a free trial option (or was, not sure if its still going on now) I am running P3D on the $9.99 per month licence and find it much more stable than FSX and most addons work flawlessly, a few developers are now making addons for both FSX and P3D (some for no extra cost!) and of course Orbx has the SBSL for PNW, PFJ, NZSI and AUS for free so as long as you bough them for FSX you can run them in P3D. Those that aren't made for P3d can be (fairly) easily installed with a little tweaking.
Think I might get the Academic version in the next month or so, was worried about the watermark before, but it took me ages to see it in the two images so not so concerned now!   :)

(i'm also over what would normally be considered Academic age, but I take the odd flying lesson now and again, so that i feel should satisfy the licence requirement!)