Thank you really for all the advice. I could buy both and return one but I am just little lazy to do that.
One reason that tickles my mind in this direction is the fact I am a chemist. I have dealt with polymer chemistry for awhile now. Not expert on polyurethanes and nitro finishes, however, I cannot ignore the fact that most high end guitars have nitro finish. The difference between 7p and above is that they claim that 1. 7p is factory made 2. 7p has poly finish and models above have nitro.
From scientific standpoint, nitrocellulose is brittle but is mixed with plasticiezers/solvents/additives to make it softer. It comes in different grades. Dow blends it with different coatings to arrive at superior properties...But polyurethane from chemical standpoint is totally different beast. What boggles my mind is that in different applications these two coatings are used in combination. You can add some isocynate to generate polyurethane function in the coating...or apply one after another but in guitar world they SEEM TO ME to be incompatible.
Now, my question is: Is there some element of sound that I am sacrificing by choosing polyurethane coated guitar? This might be like cliche topic, but do I must ask, can you guys hear the difference? Is the guitar with nitro finish more resonant, loud, with more overtones etc. than the one with poly finish? Thanks in advance