I think its really apples and oranges. I prefer the GT but I like the TR7, too. The difference is really the strange romance of the British sportscar.
The British sportscar up until the introduction of the wedge in the form of the TR7, TVR Tamsin, Lotus Eclat and a host of others, was really a romance or rhapsody on the theme of the British sportscar. It was as if they were a monument or a dedication to something that still existed. Yes, they were still British sportscars, but I don't think anyone would argue that the design language of an LBC was an anachronism in the 70's and possibly even the late 60's.
Even while the Fiat 128 was soldiering on, it at least had updated and more modern engine and a true five speed. The LBC's have the electronic OD on a four speed if there were an OD gear at all, and maintained the continental curves fans appreciate, well beyond their expiration date, not to mention things like a manual choke and shift levers the size of breaker bars, and gauge packages and dash presentation that continued in, well, a "classic" style.
The TR7 departs from this so much, I think, that an LBC nut who is caught up in the romance of the idea of the British sportscar might not take to the TR7 for the same reasons. Then of course you have what would no doubt be the finickiness of even a well sorted out LBC that must be present in the TR7 by the mere fact of its LBC-ness, and the equation is thrown off balance a bit.
I like the TR7, but I don't love it and I don't think I would grow to if I had one, I just think I would really like it. Taking an all weather trip in a GT is like sailing by yourself in the ocean in an old little schooner, it invites so many contingencies good and bad into the mix that it imparts a sense of adventure beyond mere travelling. I think that this, too, is a part of the romance of the car, and thats a property the TR7 just doesn't impart, at least to me.
In good shape they do look very good, and I like the lines of the coupe, particularly. I'm just caught up in the variations of the theme.