Dynaudio 72 vs. Dynaudio 1.3 mkii

I currently have a pair of the Audience 72's which I like quite a bit. I have read that the 1.3 mkii contour would be a significant step up in quality while sacrificing some bass output. The problem I have is the 1.3's are rear-ported and I would only be able to position them about one foot from the rear wall. The 72's are front-ported so I don't have that problem. My question then, is it worth upgrading to the 1.3's under these conditions? Am I better off staying with the 72's with the front port? My associated equipment;

McCormack DNA 125
Rogue 99 Magnum
Cary 303/100
I auditioned both while buying new speakers (because of discounts I could buy them for more or less the same price). I finally concluded that the Contours were better. However, the difference was not dramatic. It took me really a while to hear, only with specific songs, that there was a qualifying difference. In my room the Contours tend to boom if placed near the rear wall and I have then to insert the thing (forgot how you call it in English) in the port to solve that. A front-port would be a real advantage in such a situation.
Hence, in my view (hearing) it is probably not worthwhile to make the step to the 1.3 mkii's. The difference is not substantial enough to justify a large spending and there are some disadvantages (port + you will also have to buy good stands). You better save up the money to make in the future a more substantial step (the contour 1.3 SE?, the twenty five, or the new contour series?).
Of course, things me be different with your equipment.
Thanks for your input. I'll probably stay away from the rear ports until I have a situation where I can get a little farther out from the wall.