Jim, everything else being more or less equal (both SPF and Backdraft build great cars and have fine dealers), one will say to YOU based on looks alone "Buy ME!"
Here is a pic of my Backdraft and Rod Allen's VERY nice SPF at Mid Ohio to see them in the same "stance".
Some like the more "authentic" looks of the SPF and some like the "more muscular" look of the BDR. Personal opinion varies a great deal on the subject. Neither looks exactly like an original Cobra. For that matter, very few originals looked alike. Go with YOUR heart and what makes YOU happy.
Obviously, I liked the looks of the Backdraft better myself (plus at 6'5" it fits me well) or else I wouldn't have bought a Backdraft. Also, I have nothing but good things to say about my experience with Backdraft and especially with Vintage.
Wishing you many fun safe miles to you whichever one you choose!